http://www.smogon.com/dp/pokemon/typhlosion
At the Team Options part, fourth paragraph.
Blastoise is a good partner since it can switch into Water-type attacks directed at Typhlosion and use Rapid Spin to remove entry hazards, allowing Typhlosion easier switch-ins. Pairing both Blastoise and Venusaur together give an excellent defensive combination, being able to switch into each other's weaknesses and cripple the opponent's team with Sleep Powder (Venusaur) and Toxic (Blastoise).
EDIT: I don't really want to repeatedly post new posts here so I'm going to edit.
http://www.smogon.com/dp/pokemon/wailmer
Optional Changes
Wailmer only has one viable set and that is the Choice Scarf set. Rest has potential with Wailmer's huge HP and can boost Water Spout back to full power, but relying on Sleep Talk and hoping not to take a hit while sleeping is a big risk. A Choice Specs set can have some merits, but Wailmer is too slow to pull it off well. Wailmer can try to bluff Choice Scarf or Choice Specs by holding Wise Glasses, but once your opponent figures it out, Wailmer is nearly useless. Wailmer can also attempt try to abuse its mediocre Speed in a Trick Room team.
http://www.smogon.com/dp/pokemon/azelf
Counters, third paragraph
Although it fears predicted Flamethrowers, Weavile is very useful against Azelf. It outspeeds Azelf and can OHKO with Choice Band Pursuit or Night Slash. However, it should be noted that Azelf will survive a Choice Band Pursuit from a Jolly Weavile if the Azelf has 36 HP EVs. Scizor can switch in on anything but a Fire-type move and can (remove) threaten Azelf with Bullet Punch, or Pursuit if it chooses to switch. Latias is a decent switch-in on the Nasty Plot sweeper with its high Special Defense and resistances to Psychic-, Grass-, and Fire-type moves.
http://www.smogon.com/dp/pokemon/deoxys
Lead, first paragraph
Deoxys is a natural candidate for a suicide lead because of its fantastic Speed; it is only outpaced by its fellow form Deoxys-S. At first glance, this may seem outclassed by Deoxys-S, but surprisingly, this set is capable of handling other leads. Despite having miserable Defense, a couple of EVs invested into Defense can give Deoxys enough bulk to take hits from opposing leads. Shadow Ball is your main attacking option, which can deal with opposing Deoxys-S leads. With the EVs invested, it is capable of scoring a 2HKO with a Shadow Ball followed by ExtremeSpeed. If Deoxys-S uses Taunt, use Shadow Ball and follow it up with ExtremeSpeed to score an OHKO, preventing it from laying down any entry hazards. If Deoxys-S decides to go for the kill, Deoxys is capable of surviving two ExtremeSpeeds. Deoxys has a higher chance than Deoxys-S in defeating opposing Deoxys-S leads who invest 252 HP EVs. The last two slots provides entry hazards for the entire team, and works great on hyper offense teams that enjoy entry hazards being deployed early.
Second paragraph
Darkrai will always win this match-up, so make sure to bring a Scizor of your own to combat Nasty Plot versions. Make sure something reliable takes Dark Void before sending in Scizor. Kyogre makes an excellent RestTalk user thanks to its high Special Defense stat. Ho-Oh could do this as well if Stealth Rock is not present on the field. You will never take down Groudon; your best bet is to deploy hazards and switch out to Kyogre who can nullify Drought and bring in Drizzle. Opposing Kyogre leads are also troublesome. In a similar fashion to Groudon, set up your entry hazards and bring in something appropriate. Most Kyogre leads are Choiced, so bring in Latias or Palkia to take Water Spout and hopefully scare it away with Grass Knot or Thunder, respectively. If Kyogre is running a support set in the lead slot, Blissey makes a reliable switch into it.
Team Options, second paragraph
When immersed in sun radiation, you know you are up against Groudon. It is a good idea to drop Stealth Rock or Spikes before switching out. Kyogre can be a great switch-in, nullifying Drought and bringing in Drizzle. Kyogre can survive Earthquake from support Groudon and annihilate it swiftly with Surf. Beware of Toxic though; it can be a disturbance to Kyogre throughout the entire match. With the abundance of Deoxys-S leads, Kyogre is often forgotten. Similar to Groudon, lay down Stealth Rock or Spikes first before switching out. Kyogre often carries a Choice item in the lead slot; therefore, it can be great to scout out the first attack after you lay down your entry hazards. It will be much easier to articulate your thoughts after it has used its first attack. If it uses Thunder, Garchomp would probably be a wise switch-in, allowing you to set up on a switch-out. Overall, the safest switch-in to Kyogre is Blissey because it can cripple with Toxic or Thunder Wave.
Counters, first paragraph
Deoxys must be beaten by prediction and a combination (combinations gets squiggly line) of Pokémon to switch-in and resist its attacks. Some Pokémon deserve special mention: Latias wags her finger at Grass Knot, Superpower, (comma) and Thunder, OHKOes it with Dragon Pulse, and Recovers off the residual damage. If Latias sacrifices Speed EVs in favor of HP and more Special Defense, it can easily survive two Shadow Balls from Deoxys. Forretress takes Superpower, Shadow Ball, (comma) and Grass Knot like a real man, but it always gets 2HKOed by Thunder or Thunderbolt. Rayquaza resists Superpower and Grass Knot, but is 2HKOed by Shadow Ball, Thunder (which is 70% accurate against Rayquaza, though), (comma) or Thunderbolt. Rayquaza also has to watch out for Ice Beam, Ice Punch, (comma) and Rock Slide. However, by Rayquaza's very presence, Deoxys trembles; Rayquaza is extremely capable of OHKOing with ExtremeSpeed. Ho-Oh's Defense makes Deoxys' Superpower underpowered against the great phoenix, and its impressive (avoiding repetition) Special Defense can make Deoxys not so special if Deoxys doesn't have an Electric-type move. Spiritomb is immune to Superpower and Psycho Boost, and takes little from Grass Knot. It can then Pursuit or Sucker Punch the Deoxys away.
Sorry, this is getting too big. I'll stop now.
At the Team Options part, fourth paragraph.
Blastoise is a good partner since it can switch into Water-type attacks directed at Typhlosion and use Rapid Spin to remove entry hazards, allowing Typhlosion easier switch-ins. Pairing both Blastoise and Venusaur together give an excellent defensive combination, being able to switch into each other's weaknesses and cripple the opponent's team with Sleep Powder (Venusaur) and Toxic (Blastoise).
EDIT: I don't really want to repeatedly post new posts here so I'm going to edit.
http://www.smogon.com/dp/pokemon/wailmer
Optional Changes
Wailmer only has one viable set and that is the Choice Scarf set. Rest has potential with Wailmer's huge HP and can boost Water Spout back to full power, but relying on Sleep Talk and hoping not to take a hit while sleeping is a big risk. A Choice Specs set can have some merits, but Wailmer is too slow to pull it off well. Wailmer can try to bluff Choice Scarf or Choice Specs by holding Wise Glasses, but once your opponent figures it out, Wailmer is nearly useless. Wailmer can also attempt try to abuse its mediocre Speed in a Trick Room team.
http://www.smogon.com/dp/pokemon/azelf
Counters, third paragraph
Although it fears predicted Flamethrowers, Weavile is very useful against Azelf. It outspeeds Azelf and can OHKO with Choice Band Pursuit or Night Slash. However, it should be noted that Azelf will survive a Choice Band Pursuit from a Jolly Weavile if the Azelf has 36 HP EVs. Scizor can switch in on anything but a Fire-type move and can (remove) threaten Azelf with Bullet Punch, or Pursuit if it chooses to switch. Latias is a decent switch-in on the Nasty Plot sweeper with its high Special Defense and resistances to Psychic-, Grass-, and Fire-type moves.
http://www.smogon.com/dp/pokemon/deoxys
Lead, first paragraph
Deoxys is a natural candidate for a suicide lead because of its fantastic Speed; it is only outpaced by its fellow form Deoxys-S. At first glance, this may seem outclassed by Deoxys-S, but surprisingly, this set is capable of handling other leads. Despite having miserable Defense, a couple of EVs invested into Defense can give Deoxys enough bulk to take hits from opposing leads. Shadow Ball is your main attacking option, which can deal with opposing Deoxys-S leads. With the EVs invested, it is capable of scoring a 2HKO with a Shadow Ball followed by ExtremeSpeed. If Deoxys-S uses Taunt, use Shadow Ball and follow it up with ExtremeSpeed to score an OHKO, preventing it from laying down any entry hazards. If Deoxys-S decides to go for the kill, Deoxys is capable of surviving two ExtremeSpeeds. Deoxys has a higher chance than Deoxys-S in defeating opposing Deoxys-S leads who invest 252 HP EVs. The last two slots provides entry hazards for the entire team, and works great on hyper offense teams that enjoy entry hazards being deployed early.
Second paragraph
Darkrai will always win this match-up, so make sure to bring a Scizor of your own to combat Nasty Plot versions. Make sure something reliable takes Dark Void before sending in Scizor. Kyogre makes an excellent RestTalk user thanks to its high Special Defense stat. Ho-Oh could do this as well if Stealth Rock is not present on the field. You will never take down Groudon; your best bet is to deploy hazards and switch out to Kyogre who can nullify Drought and bring in Drizzle. Opposing Kyogre leads are also troublesome. In a similar fashion to Groudon, set up your entry hazards and bring in something appropriate. Most Kyogre leads are Choiced, so bring in Latias or Palkia to take Water Spout and hopefully scare it away with Grass Knot or Thunder, respectively. If Kyogre is running a support set in the lead slot, Blissey makes a reliable switch into it.
Team Options, second paragraph
When immersed in sun radiation, you know you are up against Groudon. It is a good idea to drop Stealth Rock or Spikes before switching out. Kyogre can be a great switch-in, nullifying Drought and bringing in Drizzle. Kyogre can survive Earthquake from support Groudon and annihilate it swiftly with Surf. Beware of Toxic though; it can be a disturbance to Kyogre throughout the entire match. With the abundance of Deoxys-S leads, Kyogre is often forgotten. Similar to Groudon, lay down Stealth Rock or Spikes first before switching out. Kyogre often carries a Choice item in the lead slot; therefore, it can be great to scout out the first attack after you lay down your entry hazards. It will be much easier to articulate your thoughts after it has used its first attack. If it uses Thunder, Garchomp would probably be a wise switch-in, allowing you to set up on a switch-out. Overall, the safest switch-in to Kyogre is Blissey because it can cripple with Toxic or Thunder Wave.
Counters, first paragraph
Deoxys must be beaten by prediction and a combination (combinations gets squiggly line) of Pokémon to switch-in and resist its attacks. Some Pokémon deserve special mention: Latias wags her finger at Grass Knot, Superpower, (comma) and Thunder, OHKOes it with Dragon Pulse, and Recovers off the residual damage. If Latias sacrifices Speed EVs in favor of HP and more Special Defense, it can easily survive two Shadow Balls from Deoxys. Forretress takes Superpower, Shadow Ball, (comma) and Grass Knot like a real man, but it always gets 2HKOed by Thunder or Thunderbolt. Rayquaza resists Superpower and Grass Knot, but is 2HKOed by Shadow Ball, Thunder (which is 70% accurate against Rayquaza, though), (comma) or Thunderbolt. Rayquaza also has to watch out for Ice Beam, Ice Punch, (comma) and Rock Slide. However, by Rayquaza's very presence, Deoxys trembles; Rayquaza is extremely capable of OHKOing with ExtremeSpeed. Ho-Oh's Defense makes Deoxys' Superpower underpowered against the great phoenix, and its impressive (avoiding repetition) Special Defense can make Deoxys not so special if Deoxys doesn't have an Electric-type move. Spiritomb is immune to Superpower and Psycho Boost, and takes little from Grass Knot. It can then Pursuit or Sucker Punch the Deoxys away.
Sorry, this is getting too big. I'll stop now.