First team of the year (OU)

[Sixonesix]

Lacking a reasonably powerful PC, I was forced to take a break from Pokemon for this entire winter. Now that it's spring break, I've been using my family computer for shoddy, to get back into the game enough to hopefully participate in Suspect Voting. Here's my current team so far:

Jirachi @ Choice Scarf
Adamant nature
6 HP, 252 attack, 252 speed
Iron Head
U-turn
Stealth Rock
Trick
The fastest attacker on my team, Jirachi plays a big role on my team as a round starter. I usually start off the match by setting up Stealth Rock or flinching a delicate enemy lead to death. Occasionally I use it to Trick troublesome foes, and even when busted down to 299 speed I still use it to start off after another pokemon has been taken out, and either flinch even slower pokemon with Iron Head or U-turn to an appropriate counter. Even with the Choice Scarf still on, U-turn serves the purpose of keeping it invulnerable to Magnezone leads.

Tyranitar @ Choice Band
Adamant nature
176 HP, 252 attack, 80 special defense
Pursuit
Stone Edge
Crunch
Earthquake
Tyranitar fills a niche in my team, as a cover for scRotom, Latias, and a backup to take on Heatran. It also hits everything else that switches in on it incredibly hard with Crunch or Stone Edge. Pursuit requires some prediction, and doesn't always KO the enemy pokemon, but it weakens it greatly for a sweep from it or another pokemon. The EV spread gives it 256 in each defense stat and 385 HP, a solid number. Its Sand Stream ability doesn't help my team, but at least it doesn't really hurt it either.
Tyranitar greatly appreciates Wishes from Latias, because it is frequently in situations where it does a lot of damage, but ends up taking so much damage in the process that it is rendered ineffective. Wish allows it to come back in to wreak havoc a second, or possibly even a third time. Tyranitar has gone from being a pokemon I rarely use to an MVP on my team, thanks to Wish. That's just how important Wish is.

Latias @ Leftovers
Timid nature
148 HP, 108 special attack, 252 speed
Dragon Pulse
Calm Mind
Protect
Wish
A special sponge and team supporter that can also attack well in its own right. Its typing lets it handle physical pokemon that would otherwise threaten this team, like Infernape. With access to Wish, Latias greatly enhances the longevity of my pokemon that can't recover on their own. Protect warns of any status-inducing moves, which is good because Latias really hates all of them. Dragon Pulse is its generic special attacking move, that is usually used to finish off weakened foes slower than Latias. Calm Mind is a last resort move on Latias, to use when it has nothing else to do. As such it can be replaced with any other useful move.

Gyarados @ Leftovers
Adamant nature
216 HP, 16 attack, 160 defense, 116 speed
Dragon Dance
Waterfall
Body Slam
Substitute
Works much better than the Salamence I previously used in this slot. Though it lacks the incredible destructive power Salamence had after a single Dragon Dance, it is far more durable and is safer to set up. The first two moves are predictable on any Gyarados, Dragon Dance to gain speed and power and Waterfall for a good STAB move. Substitute allows me to predict what my opponent is going to do, and is one of the reasons why Wish support from Latias is invaluable for this Gyarados. Having only two attack moves, Body Slam serves a good compromise for the many other attacking moves Gyarados could use in that slot. It hits most pokemon for neutral damage that Waterfall cannot, is fairly strong, and can paralyze. With Body Slam, it can actually do something to Celebi from behind a sub (until it gets broken) and will not lose a double Gyara fight like it would if it had Earthquake instead.

Magnezone @ Choice Scarf
Naive nature
6 HP, 252 special attack, 252 speed
Thunderbolt
Hidden Power Fire
Flash Cannon
Explosion
This is my option against most steels, so this is pretty important for my team. Choice scarf guarantees that it'll be faster than all other steels it would want to hit, except for Jirachi, and allows it to catch other pokemon by surprise. Thunderbolt is a general STAB move. Hidden Power Fire gives me an easier time against Scizor and other pokemon that are exceptionally weak to it, and is the best Hidden Power choice for it since it is used almost solely to fight steels, and not dragons or (god forbid) ground types. Everything beyond those two moves is really filler, so I've got Flash Cannon for a second STAB and Explosion to take out troublesome enemies. I really question whether its tradeoff for less special defense is worth it, though.

Celebi @ Leftovers
Bold nature
252 HP, 224 defense, 32 speed
Energy Ball
Reflect
Thunder Wave
Recover
Simply awesome. Thunder Wave to slow down the enemy, and Reflect to soften physical attacks. Walls the hell out of nearly all physical attackers, including and especially Gyarados. This singlehandedly subdued an entire rain dance team once. I prefer Energy Ball to Grass Knot because I hate using moves that vary in base power as my only attack. For the things Grass Knot hits hard, Energy Ball can hits reasonably hard enough, and it doesn't leave Celebi helpless the the lightweight pokemon Grass Knot can hardly scratch. The chance for a special defense down also helps in a last-pokemon stall war.


Common enemies:
Azelf - Jirachi could flinch it to death, or Tyranitar can Pursuit it to death. Normally it will just explode on its own, in which case I try to get a Reflect up with Latias.
Breloom - Spore is annoying, but beyond that Celebi walls everything it has.
Celebi - Enemy Celebi are tough to take out. My best option is Tyranitar.
Dugtrio - I just deal with it with whatever I happen to be fighting it with. Latias and Celebi do fine.
Electivire - Hard to deal with. Celebi, normally my general physical stopper, can't paralyze it, and is weak to Ice Punch. Energy Ball hurts a bit, but a critical hit against my favor will always mean death.
Empoleon - Fast ones won't like being paralyzed by Celebi, and it can't do much to Latias.
Flygon - Also hard to deal with. It's often choiced, so it comes down to a prediction war.
Gengar - Scizor used to deal with it very well, but without it my best option is Jirachi or *shudder* Tyranitar. Not easy to fight.
Gliscor - Celebi and Latias both work well.
Gyarados - CELEBI. Gyara can't do a thing to it unless Celebi's already on the verge of death.
Heatran - Latias walls is pretty well, but can't attack in turn right away. I always Reflect expecting an Explosion, which Latias will survive.
Heracross - Salamence does alright.
Infernape - Latias walls everything it has.
Jirachi - Ooh, these are as annoying to fight as Togekiss...Celebi can win if it doesn't have to take too many Iron Heads.
Kingdra - Like with Gyarados, Celebi walls everything it has, though Draco Meteor hurts.
Latias - Tyranitar can kill it with Pursuit.
Lucario - Celebi can stop it before it gets too powerful.
Machamp - Celebi walls everything it has, even Ice Punch isn't too worrisome.
Magnezone - These are also hard to deal with. Tyranitar and Latias are probably my best options.
Mamoswine - Celebi works well, and Magnezone does alright.
Metagross - Celebi shuts it down, but can't really kill it; and Tyranitar kills it, but can't fight it for more than a turn or so.
Ninjask - Jirachi doesn't do too well against it, unfortunately. They aren't common, however.
Porygon-Z - Magnezone can dispatch it with little trouble.
Rhyperior - Tyranitar, Latias, Celebi, Jirachi, and Salamence can all work.
Roserade - Jirachi can flinch it to death with Iron Head. Celebi can also stop it.
scRotom-A - Tyranitar can take it down, but Will-o-Wisp is horribly annoying.
Salamence - Latias can come in after a pokemon has been taken out, but can't switch in directly. Celebi can shut it down despite Fire Blast, and (I thought) Tyranitar can kill it with Stone Edge. Celebi is the only one that can handle it if it has a DD though.
Scizor - Magnezone traps and kills it.
Snorlax - Tyranitar hits it hard with Stone Edge.
Starmie - Latias can take it's attacks reasonably well and hit it back.
Suicune - Hard to deal with. Celebi can paralyze it and Latias can Calm Mind with it, but that's it.
Togekiss - Jirachi outspeeds Choice Scarf versions and can outflinch it. Latias can deal with slower versions.
Tyranitar - Jirachi can flinch it to death with Iron Head, but that's about it.
Weavile - Shut down by Celebi, and Magnezone walls it except for Brick Break.
Yanmega - Hard to deal with. Salamence is probably my best option.
Zapdos - Tyranitar can kill it while it struggles to do severe damage back.

Another issue with this team is that it tends to get done in hard by status-based teams. Most of my pokemon can't afford to be afflicted with paralysis, burns, and especially poison. Celebi can take burns and paralysis alright, but due to its stallish nature, it hates being poisoned repeatedly. Since Tyranitar switches in and out frequently, it can handle poison well enough, and paralysis isn't too big of a deal since it's already slow. But being burned completely ruins it. Latias, as mentioned above, strongly dislikes all forms of status, as does Gyarados if it's caught out of sub. Jirachi is immune to poison, but is rendered unusable if paralyzed or burned. Magnezone is really the only one on my team that can deal with all of the statuses mentioned above, but is ruined if it is put to sleep. As is everyone else on my team except maybe Celebi. I'm hoping for a suggestion of how to fix this large hole in my team.

 

[Darkmalice]

Celebi should have Leech Seed in place of Reflect. This makes dealing with walls like Suicune, Togekiss, Hippowdon and even Blissey considerably easier, using their high HP to heal your team. Leech Seed hits any switch-in to Celebi besides opposing Celebi and Breloom (both of whom wouldn't switch into Celebi). Latias already has Reflect should you need the extra Defense. Jirachi can switch in on any of Tyranitar's attacks except Earthquake, which is a free Latias or Salamence switch-in - just use prediction against the feared dinosaur.

I recommend Grass Knot in place of Energy Ball. More often than not, you will find that Grass Knot is more likely to hit a pokemon harder than Energy Ball than the other way round. This is especially the case when considering which pokemon you would use Grass Knot on - Gyarados especially. I would only use Energy Ball in the Suspect Ladder thanks to Manaphy.

By the way, I don't quite agree with your threat list. Celebi deals with Electivire well; it doesn't get 2HKOed by Ice Punch, meaning it can switch-in on the Electrivire, Recover off the damage, and wear him down with Leech Seed and Grass Knot. Magnezone's only real threat is trapping Jirachi or Magnezone locked into the wrong move. But you can't solve that problem. Magnezone is forced to explode against Salamence and Latias, whilst Tyranitar and Celebi have no problems against the magnet.

 

[iKitsune]

I would stick Hp fire on Celebi after a bit of residual damge scizor will go down from it. For this reason i would not bother with leech seed as the primary switches into celebi will hate either hp fire twave or grass knot. I have used this celebi to much success in the past so i know it works well.

Apart from that your tactic should should work suerbly baiting in steels and then annihilating them with latias. For this reason im sure this team has a high win ratio as anyway to get off a DD mence sweep with scizor (gone with magnezone) and scarfers like gengar (gone with ttar) should ensure plenty of victories.

Just use 252 hp on ttar as he needs the HP for sp def more.

 

[Sixonesix]

Updated the OP, with more detail, a new pokemon, and a new move.

Celebi should have Leech Seed in place of Reflect. This makes dealing with walls like Suicune, Togekiss, Hippowdon and even Blissey considerably easier, using their high HP to heal your team. Leech Seed hits any switch-in to Celebi besides opposing Celebi and Breloom (both of whom wouldn't switch into Celebi). Latias already has Reflect should you need the extra Defense. Jirachi can switch in on any of Tyranitar's attacks except Earthquake, which is a free Latias or Salamence switch-in - just use prediction against the feared dinosaur.

I recommend Grass Knot in place of Energy Ball. More often than not, you will find that Grass Knot is more likely to hit a pokemon harder than Energy Ball than the other way round. This is especially the case when considering which pokemon you would use Grass Knot on - Gyarados especially. I would only use Energy Ball in the Suspect Ladder thanks to Manaphy.

By the way, I don't quite agree with your threat list. Celebi deals with Electivire well; it doesn't get 2HKOed by Ice Punch, meaning it can switch-in on the Electrivire, Recover off the damage, and wear him down with Leech Seed and Grass Knot. Magnezone's only real threat is trapping Jirachi or Magnezone locked into the wrong move. But you can't solve that problem. Magnezone is forced to explode against Salamence and Latias, whilst Tyranitar and Celebi have no problems against the magnet.

Leech Seed is good, but I find Reflect to be too useful for me to give up. For example, there are many times when I will have paralyzed a pokemon that would normally 2HKO Celebi, and I prefer setting up a Reflect and having their attacks do half damage than just using Recover repeatedly. It also helps against physical attackers that Celebi can't paralyze. Plus, now that Latias has Wish, I believe it is even more important that Celebi have Reflect.
As for the choice for Energy Ball, that's just because I hate being stuck against pokemon due to weight issues, when it already isn't terrible at damaging those pokemon with Energy Ball that it doesn't have trouble hitting with Grass Knot.

I would stick Hp fire on Celebi after a bit of residual damge scizor will go down from it. For this reason i would not bother with leech seed as the primary switches into celebi will hate either hp fire twave or grass knot. I have used this celebi to much success in the past so i know it works well.

Apart from that your tactic should should work suerbly baiting in steels and then annihilating them with latias. For this reason im sure this team has a high win ratio as anyway to get off a DD mence sweep with scizor (gone with magnezone) and scarfers like gengar (gone with ttar) should ensure plenty of victories.

Just use 252 hp on ttar as he needs the HP for sp def more.

I try not to let Celebi fight Scizor fearing a bug move, which will do heavy damage no matter what. Also Latias...doesn't do too well against steels with only Dragon Pulse?

Also the 80 EVs in special defense increases Tyranitar's ability to take special hits more than putting all of the EVs into HP would because the ratio of the number of points gained from the EVs to its special defense stat without them is smaller than the ratio of the # of points gained to its HP without the points.