Soul Dew-less =/= useless
http://www.serebii.net/pokedex-bw/380.shtml
[Overview]
<p>With the introduction of BW, it seems that Latias has lost what had made her so useful in Ubers in previous generations: her held item, Soul Dew. Due to this, she cannot operate as the deadly offensive pivot that she used to be able to. However, Latias's usefulness can still be salvaged even without Soul Dew. Her naturally high Special Defense and access to Calm Mind still make her an alternative check to Kyogre, arguably the most dominant Pokemon in the tier. Play Latias carefully, and she can still be a huge asset to an Ubers team.</p>
[SET]
name: Uber Calm Mind
move 1: Calm Mind
move 2: Dragon Pulse
move 3: Recover
move 4: Psyshock / Thunder
item: Leftovers
nature: Calm
evs: 252 HP / 4 SpA / 252 SpD
[SET COMMENTS]
<p>The loss of Soul Dew hit Latias very hard, but as an extremely versatile Pokemon from the beginning, she has been able to adjust and reinvent herself with the change of circumstances. Latias is still an extremely resilient Calm Mind user in the Uber tier. While Grass Arceus, Palkia, and Gastrodon seem like better candidates for checking Kyogre, she still has a number of perks over them. Firstly, her ability, Levitate, renders Latias immune to Spikes and Toxic Spikes, hazards that are prevalent in the Uber metagame. Unlike Gastrodon, Latias can become a long term threat should her counters fall, as she can slowly build up Calm Minds and sweep. Latias also has access to Recover unlike Palkia, making her a longer lasting check to Kyogre. Grass Arceus is a decent check to Kyogre, but being worn down by Spikes could potentially allow it to become 2HKOed by Choice Scarf Water Spout. The biggest catch of using Latias, however, is the fact that the player does not have to run Grass Arceus as a long term check to Kyogre, freeing up a team slot to run a more potent variant such as Extreme Killer Arceus.</p>
<p>Calm Mind allows Latias to boost up alongside other Calm Mind users in Ubers that Latias can defeat one-on-one, including Kyogre, Manaphy, and various formes of Arceus. Dragon Pulse is Latias's most reliable STAB attack. Recover allows her to keep herself healthy and repeatedly come into battle. The final slot is up to the player, and should reflect Latias's overall function. Psyshock allows Latias to bypass the boosts of other Calm Mind users by hitting on their weaker defense, while Thunder is geared further toward countering Kyogre. Either attack is acceptable, since Psyshock is another reliable STAB and hits Blaziken for super effective damage, while Thunder offers Latias the opportunity to hit Steel-types, and a 30% paralysis chance is never bad.</p>
[ADDITIONAL COMMENTS]
<p>The EVs are rather simple. Max HP and max Special Defense allows Latias to take huge amounts of special abuse and still live to tell the tale. For example, she can easily avoid being 2HKOed by Choice Scarf Water Spout in the rain after Stealth Rock and Leftovers. Here are some damage calculations to solidify this point:</p>
<ul class="damage_calculation">
<li>Modest Choice Scarf Kyogre's Water Spout in rain vs +0 Latias: 37.09% - 43.68%</li>
<li>Neutral Choice Scarf Palkia's Spacial Rend vs +1 Latias: 40.11% - 47.80%</li>
<li>Timid Choice Specs Reshiram's Blue Flare in sun vs +0 Latias: 43.41% - 51.10%</li>
<li>0 SpA +1 Arceus's Ice Beam (non-STAB) vs +0 Latias: 39.56% - 46.70%</li>
<li>0 SpA +1 Arceus's Ice Beam (non-STAB) vs +1 Latias: 26.37% - 31.32%</li>
</ul>
<p>96 EVs can be moved from Special Defense to Speed, allowing Latias to outspeed Pokemon with base 90 Speed and a neutral nature, but that is the maximum Latias should run, as taking too many Special Defense EVs away would mean she cannot switch into Choice Scarf Kyogre any more.</p>
<p>Hidden Power Fire can be used in the sun to hit Steel-types, but since Latias's main job is to check Kyogre, Thunder is the better option. Roar can be used to defeat other Calm Mind users that lack Roar without having to wait for a critical hit, and it also lets Latias phaze out Mewtwo in a pinch. Draco Meteor is another option over Dragon Pulse if Psyshock is used, as it allows Latias to OHKO Palkia after Stealth Rock damage without using Calm Mind—while surviving Lustrous Orb-boosted Spacial Rend—and deal respectable damage to Dialga, but tends to works against Calm Mind.</p>
<p>Latias excels in teams in which running other Kyogre checks, most notably Grass Arceus, is impractical. A sun team is one of the most obvious examples, as Grass Arceus becomes a huge liability against Pokemon who spam Fire-type attacks. Since Latias encourages the use of other Arceus formes, formes who synergize well with Latias are obviously good teammates. Normal Arceus can switch into Ghost-type attacks aimed at Latias, while Latias can switch into Fighting-type attacks in return. Fighting and Steel Arceus also take on Latias's weaknesses extremely well. Water Arceus can switch into Ice-type attacks, while Latias can take Electric- and Grass-type attacks for it. Rock, Dark, and Fire Arceus also synergize well with Latias.</p>
<p>Ferrothorn walls Latias, uses Leech Seed on her, and sets up Spikes for free. Chansey and Blissey can take anything Latias uses and use Toxic on her. Tyranitar laughs at everything Latias uses and checkmates her with Pursuit and Crunch. Lucario, Excadrill, Terrakion, Scizor, and Fighting Arceus can easily scare out all four and set up on them, although Fighting Arceus cannot set up on Chansey and Blissey. Ho-Oh can switch into the first three with ease—be sure to avoid Leech Seed or a status move—set up a Substitute, and pound away at the opposition with Sacred Fire and Brave Bird. Heatran synergizes with Latias perfectly, while stallbreaking with Taunt, Toxic, and Roar. A Ferrothorn of your own synergizes well with Latias and can set up Spikes.</p>
[SET]
name: Uber Dual Screen
move 1: Reflect
move 2: Light Screen
move 3: Healing Wish
move 4: Dragon Pulse / Wish / Recover
item: Light Clay
nature: Timid
evs: 252 HP / 4 Def / 252 Spe
[SET COMMENTS]
<p>With Latias's decent base 110 Speed, excellent Special Defense, and numerous resistances, she can set up dual screens for the team without many problems at all. While Latias may seem to be outclassed by Cresselia, her higher Speed, better resistances, and ability to hurt things differentiates her from the moon swan. The easiest way to play Latias is to send in a sweeper and do as much damage to the opposition as it can while avoiding being KOed. Once its counters are removed, send in Latias, set up Reflect and Light Screen, then use Healing Wish to bring the sweeper in for a second chance at sweeping.</p>
<p>The final move is variable. Dragon Pulse is a reliable STAB move, stopping Latias from turning into Taunt fodder. Wish gives the recipient a relatively safe switch-in without having to sacrifice Latias, while Recover gives Latias reliable recovery, allowing her to come in repeatedly to set up dual screens.</p>
[ADDITIONAL COMMENTS]
<p>The EV spread gives Latias maximum Speed and bulk. Max Special Defense can be used instead of max Speed so Latias can still switch into Kyogre, but since her main advantage over Cresselia is her Speed, that should be taken advantage of as much as possible. Hidden Power Fire can be used in the last spot to deter Ferrothorn and Forretress from setting up hazards too freely, but is quite useless otherwise. Magic Coat can also be useful to bounce back Taunt.</p>
<p>There are too many good dual screens recipients in Ubers to list. Double Dance Groudon is possibly the best, because it synergises well with Latias, and getting +2 / +2 becomes quite easy with dual screens up. Extreme Killer Arceus, Rayquaza, Double Dance Terrakion, Darkrai, Mewtwo, Blaziken, and Swords Dance Garchomp are just a few of the very powerful sweepers that become a lot more intimidating with dual screens support. Baton Pass users such as Gorebyss and Mew are also much harder to stop when Reflect and Light Screen are up, and especially difficult to deal with if given a second chance with Healing Wish.</p>
<p>Taunt is almost a surefire way to stop Latias, unless she uses Magic Coat. Fortunately for Latias, Taunt is relatively rare in Ubers. Deoxys-S is hardly seen, and Latias outspeeds Heatran, so she can get at least one screen up or pull off Healing Wish. Furthermore, Taunt variants of Mewtwo are rarely, if ever, seen. Tyranitar can defeat all three, surviving a +1 Aura Sphere from Taunt Mewtwo if necessary. Kyogre also defeats them with its flippers down.</p>
[Other Options]
<p>Latias has a few other coverage moves that she can use, namely Surf and Grass Knot. However, since her main job is to check Kyogre and other Calm Mind users, the moves given are the most effective. Refresh allows Latias to shrug off Toxic that Blissey and Chansey throw at her. Thunder Wave and Toxic are useful, but generally, neither is worth a slot. Substitute can be used to scout switches and allow Latias to escape from Pursuit. Charm can be also be used, but Reflect is better in most circumstances. Choice Specs and Choice Scarf are also usable, but such sets are better left to stronger Dragon-types such as Palkia, Dialga, and Reshiram.</p>
[Checks and Counters]
<p>Tyranitar can take virtually everything from Latias and checkmate her with Crunch and Pursuit. Blissey and Chansey wall Latias completely and cripple her with Toxic. Steel-types in general wall Latias comfortably. Ferrothorn can use Leech Seed on her and set up hazards for free, Steel Arceus laughs at everything she uses, and Jirachi can use Thunder Wave and Iron Head to take her out, while Scizor and Metagross can checkmate her in a similar fashion to Tyranitar. Even Lucario can take a hit or two from uninvested Latias. Arceus forms with Roar or a super effective STAB—such as Dark Arceus—beat Latias one-on-one. Finally, Latias can be revenge killed by any strong physical attacker with a super effective STAB or an overpowered super effective special attack, such as Draco Meteor from Dialga or Palkia.</p>
[Dream World]
<p>While Latias does not get a Dream World ability, she gets her fantastic hold item, Soul Dew, back. With it, she can unlock her secret Super Saiyan 2 power to become one of the most useful and versatile Pokemon in the Uber metagame. Heavy investment in Special Defense is no longer needed to take on enemies such as Kyogre, allowing her to invest more in Speed and Special Attack, allowing Latias to thus serve as the offensive pivot she had been in past generations. No longer will you have to rely on make-shift Kyogre counters such as Grass Arceus and Gastrodon either; Soul Dew Latias will have the accursed sea leviathan firmly under her boot.</p>

http://www.serebii.net/pokedex-bw/380.shtml
[Overview]
<p>With the introduction of BW, it seems that Latias has lost what had made her so useful in Ubers in previous generations: her held item, Soul Dew. Due to this, she cannot operate as the deadly offensive pivot that she used to be able to. However, Latias's usefulness can still be salvaged even without Soul Dew. Her naturally high Special Defense and access to Calm Mind still make her an alternative check to Kyogre, arguably the most dominant Pokemon in the tier. Play Latias carefully, and she can still be a huge asset to an Ubers team.</p>
[SET]
name: Uber Calm Mind
move 1: Calm Mind
move 2: Dragon Pulse
move 3: Recover
move 4: Psyshock / Thunder
item: Leftovers
nature: Calm
evs: 252 HP / 4 SpA / 252 SpD
[SET COMMENTS]
<p>The loss of Soul Dew hit Latias very hard, but as an extremely versatile Pokemon from the beginning, she has been able to adjust and reinvent herself with the change of circumstances. Latias is still an extremely resilient Calm Mind user in the Uber tier. While Grass Arceus, Palkia, and Gastrodon seem like better candidates for checking Kyogre, she still has a number of perks over them. Firstly, her ability, Levitate, renders Latias immune to Spikes and Toxic Spikes, hazards that are prevalent in the Uber metagame. Unlike Gastrodon, Latias can become a long term threat should her counters fall, as she can slowly build up Calm Minds and sweep. Latias also has access to Recover unlike Palkia, making her a longer lasting check to Kyogre. Grass Arceus is a decent check to Kyogre, but being worn down by Spikes could potentially allow it to become 2HKOed by Choice Scarf Water Spout. The biggest catch of using Latias, however, is the fact that the player does not have to run Grass Arceus as a long term check to Kyogre, freeing up a team slot to run a more potent variant such as Extreme Killer Arceus.</p>
<p>Calm Mind allows Latias to boost up alongside other Calm Mind users in Ubers that Latias can defeat one-on-one, including Kyogre, Manaphy, and various formes of Arceus. Dragon Pulse is Latias's most reliable STAB attack. Recover allows her to keep herself healthy and repeatedly come into battle. The final slot is up to the player, and should reflect Latias's overall function. Psyshock allows Latias to bypass the boosts of other Calm Mind users by hitting on their weaker defense, while Thunder is geared further toward countering Kyogre. Either attack is acceptable, since Psyshock is another reliable STAB and hits Blaziken for super effective damage, while Thunder offers Latias the opportunity to hit Steel-types, and a 30% paralysis chance is never bad.</p>
[ADDITIONAL COMMENTS]
<p>The EVs are rather simple. Max HP and max Special Defense allows Latias to take huge amounts of special abuse and still live to tell the tale. For example, she can easily avoid being 2HKOed by Choice Scarf Water Spout in the rain after Stealth Rock and Leftovers. Here are some damage calculations to solidify this point:</p>
<ul class="damage_calculation">
<li>Modest Choice Scarf Kyogre's Water Spout in rain vs +0 Latias: 37.09% - 43.68%</li>
<li>Neutral Choice Scarf Palkia's Spacial Rend vs +1 Latias: 40.11% - 47.80%</li>
<li>Timid Choice Specs Reshiram's Blue Flare in sun vs +0 Latias: 43.41% - 51.10%</li>
<li>0 SpA +1 Arceus's Ice Beam (non-STAB) vs +0 Latias: 39.56% - 46.70%</li>
<li>0 SpA +1 Arceus's Ice Beam (non-STAB) vs +1 Latias: 26.37% - 31.32%</li>
</ul>
<p>96 EVs can be moved from Special Defense to Speed, allowing Latias to outspeed Pokemon with base 90 Speed and a neutral nature, but that is the maximum Latias should run, as taking too many Special Defense EVs away would mean she cannot switch into Choice Scarf Kyogre any more.</p>
<p>Hidden Power Fire can be used in the sun to hit Steel-types, but since Latias's main job is to check Kyogre, Thunder is the better option. Roar can be used to defeat other Calm Mind users that lack Roar without having to wait for a critical hit, and it also lets Latias phaze out Mewtwo in a pinch. Draco Meteor is another option over Dragon Pulse if Psyshock is used, as it allows Latias to OHKO Palkia after Stealth Rock damage without using Calm Mind—while surviving Lustrous Orb-boosted Spacial Rend—and deal respectable damage to Dialga, but tends to works against Calm Mind.</p>
<p>Latias excels in teams in which running other Kyogre checks, most notably Grass Arceus, is impractical. A sun team is one of the most obvious examples, as Grass Arceus becomes a huge liability against Pokemon who spam Fire-type attacks. Since Latias encourages the use of other Arceus formes, formes who synergize well with Latias are obviously good teammates. Normal Arceus can switch into Ghost-type attacks aimed at Latias, while Latias can switch into Fighting-type attacks in return. Fighting and Steel Arceus also take on Latias's weaknesses extremely well. Water Arceus can switch into Ice-type attacks, while Latias can take Electric- and Grass-type attacks for it. Rock, Dark, and Fire Arceus also synergize well with Latias.</p>
<p>Ferrothorn walls Latias, uses Leech Seed on her, and sets up Spikes for free. Chansey and Blissey can take anything Latias uses and use Toxic on her. Tyranitar laughs at everything Latias uses and checkmates her with Pursuit and Crunch. Lucario, Excadrill, Terrakion, Scizor, and Fighting Arceus can easily scare out all four and set up on them, although Fighting Arceus cannot set up on Chansey and Blissey. Ho-Oh can switch into the first three with ease—be sure to avoid Leech Seed or a status move—set up a Substitute, and pound away at the opposition with Sacred Fire and Brave Bird. Heatran synergizes with Latias perfectly, while stallbreaking with Taunt, Toxic, and Roar. A Ferrothorn of your own synergizes well with Latias and can set up Spikes.</p>
[SET]
name: Uber Dual Screen
move 1: Reflect
move 2: Light Screen
move 3: Healing Wish
move 4: Dragon Pulse / Wish / Recover
item: Light Clay
nature: Timid
evs: 252 HP / 4 Def / 252 Spe
[SET COMMENTS]
<p>With Latias's decent base 110 Speed, excellent Special Defense, and numerous resistances, she can set up dual screens for the team without many problems at all. While Latias may seem to be outclassed by Cresselia, her higher Speed, better resistances, and ability to hurt things differentiates her from the moon swan. The easiest way to play Latias is to send in a sweeper and do as much damage to the opposition as it can while avoiding being KOed. Once its counters are removed, send in Latias, set up Reflect and Light Screen, then use Healing Wish to bring the sweeper in for a second chance at sweeping.</p>
<p>The final move is variable. Dragon Pulse is a reliable STAB move, stopping Latias from turning into Taunt fodder. Wish gives the recipient a relatively safe switch-in without having to sacrifice Latias, while Recover gives Latias reliable recovery, allowing her to come in repeatedly to set up dual screens.</p>
[ADDITIONAL COMMENTS]
<p>The EV spread gives Latias maximum Speed and bulk. Max Special Defense can be used instead of max Speed so Latias can still switch into Kyogre, but since her main advantage over Cresselia is her Speed, that should be taken advantage of as much as possible. Hidden Power Fire can be used in the last spot to deter Ferrothorn and Forretress from setting up hazards too freely, but is quite useless otherwise. Magic Coat can also be useful to bounce back Taunt.</p>
<p>There are too many good dual screens recipients in Ubers to list. Double Dance Groudon is possibly the best, because it synergises well with Latias, and getting +2 / +2 becomes quite easy with dual screens up. Extreme Killer Arceus, Rayquaza, Double Dance Terrakion, Darkrai, Mewtwo, Blaziken, and Swords Dance Garchomp are just a few of the very powerful sweepers that become a lot more intimidating with dual screens support. Baton Pass users such as Gorebyss and Mew are also much harder to stop when Reflect and Light Screen are up, and especially difficult to deal with if given a second chance with Healing Wish.</p>
<p>Taunt is almost a surefire way to stop Latias, unless she uses Magic Coat. Fortunately for Latias, Taunt is relatively rare in Ubers. Deoxys-S is hardly seen, and Latias outspeeds Heatran, so she can get at least one screen up or pull off Healing Wish. Furthermore, Taunt variants of Mewtwo are rarely, if ever, seen. Tyranitar can defeat all three, surviving a +1 Aura Sphere from Taunt Mewtwo if necessary. Kyogre also defeats them with its flippers down.</p>
[Other Options]
<p>Latias has a few other coverage moves that she can use, namely Surf and Grass Knot. However, since her main job is to check Kyogre and other Calm Mind users, the moves given are the most effective. Refresh allows Latias to shrug off Toxic that Blissey and Chansey throw at her. Thunder Wave and Toxic are useful, but generally, neither is worth a slot. Substitute can be used to scout switches and allow Latias to escape from Pursuit. Charm can be also be used, but Reflect is better in most circumstances. Choice Specs and Choice Scarf are also usable, but such sets are better left to stronger Dragon-types such as Palkia, Dialga, and Reshiram.</p>
[Checks and Counters]
<p>Tyranitar can take virtually everything from Latias and checkmate her with Crunch and Pursuit. Blissey and Chansey wall Latias completely and cripple her with Toxic. Steel-types in general wall Latias comfortably. Ferrothorn can use Leech Seed on her and set up hazards for free, Steel Arceus laughs at everything she uses, and Jirachi can use Thunder Wave and Iron Head to take her out, while Scizor and Metagross can checkmate her in a similar fashion to Tyranitar. Even Lucario can take a hit or two from uninvested Latias. Arceus forms with Roar or a super effective STAB—such as Dark Arceus—beat Latias one-on-one. Finally, Latias can be revenge killed by any strong physical attacker with a super effective STAB or an overpowered super effective special attack, such as Draco Meteor from Dialga or Palkia.</p>
[Dream World]
<p>While Latias does not get a Dream World ability, she gets her fantastic hold item, Soul Dew, back. With it, she can unlock her secret Super Saiyan 2 power to become one of the most useful and versatile Pokemon in the Uber metagame. Heavy investment in Special Defense is no longer needed to take on enemies such as Kyogre, allowing her to invest more in Speed and Special Attack, allowing Latias to thus serve as the offensive pivot she had been in past generations. No longer will you have to rely on make-shift Kyogre counters such as Grass Arceus and Gastrodon either; Soul Dew Latias will have the accursed sea leviathan firmly under her boot.</p>