Yveltal

Yveltal, The Destruction Pokémon. When this legendary Pokémon's wings and tail feathers spread wide and glow red, it absorbs the life force of living creatures. When its life comes to an end, it absorbs the life energy of every living thing and turns into a cocoon once more.

Overview

The foil to Xerneas, Yveltal represents destruction to Xerneas and creation in the lore of XY. Competitively however it's arguable the opposite, while Xerneas has cemented itself as one of the most potent sweepers in Ubers Yveltal acts as glue to a team and helps the gears work. Yveltal is one of the most flexible Pokemon in the tier, similar to Necrozma Dusk Mane and Ho-Oh, where it can be a wallbreaker, stallbreaker, or revenge killer. All this is wrapped up with one of the best healing moves in the game, good typing, and a solid ability complemented with a nice movepool. Yveltal may not be the most flashy Pokemon like Xerneas or Mega Salamence, but it is equally one of the most important Pokemon on a team.
Positives
Utility - Yveltal is one of the few Pokemon that when seen in team preview doesn't show its hand per say. With its immense flexibility Yveltal can easily catch the opponent off guard at lower levels of play than the top, and sometimes even at high level play it can be tricky to guess its set. This is more important than it first seems as it changes how Yveltal is answered to how it should be, switching a wall into Yveltal expecting a Choice Band and get hit with a Toxic or Special Attack can just cripple something or just leave a whole in the opponent's team. This in conjunction with the ability to bend to the rest of the team makes it a Pokemon that should never be overlooked when teambuilding.

Negatives
Speed - 99 base Speed is definitely OK, but this makes Yveltal outpaced by a lot of common Uber threats without a Scarf, such as Arceus in most forms and Mega Salamence. Even with a Choice Scarf, Yveltal loses to Scarfed Mewtwo and Pheromosa, and ties with Genesect. This isn't too bad but it can be an issue in some situations, especially if you lose the Speed tie and thus take more damage than needed/expected.

Abilities

Dark Aura - Increases the power of Dark moves by 33% - This isn't a game changer but it's far from bad. This can make Dark Pulse hit harder which is never bad as Dark is a good offensive STAB, and it allows for Yveltal to hit hard even with defensive sets.

Movesets

Utility

-Dark Pulse
-Oblivion Wing
-Taunt
-Sucker Punch / Toxic / U-Turn / Heat Wave
Item Attached: Life Orb
Ability: Dark Aura
EVs and Nature:
4 Atk /252 SpAtk / 252 Speed
Mild Nature

With Dark Pulse as its primary STAB and Oblivion Wing as a backup and option to keep in peak shape, Yveltal can threaten a lot with just neutral damage. Taunt fits in nicely to cripple walls, especially with Toxic in the last slot and also stops boosting sweepers. Sucker Punch can revenge kill threats that are faster but the slot is open to other options such Toxic to catch defensive threats such as the defensive Arceus forms, U-Turn for pressure and momentum, or Heat Wave to hit Ferrothorn and Magearna harder.

Maximum offensive investment makes Yveltal as strong and fast as possible, with a Mild nature giving it as much power as possible. If not using a physical move though, then Modest is ideal since there's no need to lower Yveltal's bulk for no reason. Life Orb is also very nice on Yveltal because Oblivion Wing's big recovery helps offset the recoil, making it an ideal choice for an offensive set.

Choice Specs

-Dark Pulse
-Oblivion Wing
-U-Turn
-Heat Wave / Focus Blast
Item Attached: Choice Specs
Ability: Dark Aura
EVs and Nature:
4 Def /252 SpAtk / 252 Speed
Timid Nature

Dark Pulse is the primary STAB having slightly more base power than Oblivion Wing with Dark Aura factored in. U-Turn allows Yveltal to scout threats and bait things in to be KOed by a teammate such as Mega Gengar who can trap them. Finally Heat Wave allows Yveltal to secure a 2HKO on Magearna and threaten Klefki and Ferrothorn, but Focus Blast can be an option to OHKO Tyranitar through Chople Berry and threaten Arceus Dark and Arceus Rock.

With the lack of move flexibility, Timid nature is ideal on this set to ensure as many foes as possible. The Choice Specs gives Yveltal plenty of power anyway, though otherwise the EV spread maximizes offensive potential as one would expect for a wallbreaker.

Defensive/Stallbreaker

-Foul Play / Dark Pulse
-Toxic
-Taunt / Defog / Sucker Punch
-Roost
Item Attached: Leftovers
Ability: Dark Aura
EVs and Nature:
248 HP / 76 SpDef / 184 Speed
Timid Nature

Working as a Stallbreaker, Yveltal only runs a Dark STAB for damage, Foul Play beats boosting sweepers that some bulkier teams keep as a fail safe while Dark Pulse will be better against some pure stall teams that don't use Attack EVs. Toxic and Taunt work hand in hand here to make Yveltal a Stallbreaker, crippling walls while Taunting them to prevent them from using forms of recovery which can break the backbone of bulky teams. If stallbreaking isn't necessary then one of those moves can be dropped for a utility move such as Defog or Sucker Punch. Finally Roost allows Yveltal to stay around for a while.

The given EV spread gives Yveltal the Speed it needs to Taunt foes such as defensive Arceus forms so that it can effectively stallbreak them. However, a physically defensive spread with a defense boosting nature is ideal for a more defense-focused set. Leftovers is used to provide as extra longevity, though Charti Berry is an option to catch Tyranitar with a Toxic or help with a stray Stone Edge.

Revenge Killer

-Foul Play
-U-Turn
-Defog / Knock Off
-Toxic
Item Attached: Choice Scarf
Ability: Dark Aura
EVs and Nature:
72 HP / 252 Def / 184 Speed
Jolly Nature

With Foul Play, Bulky Scarfed Yveltal acts as an amazing counter to boosting sweepers such as Rayquaza and Mega Salamence as it can take a hit and threaten either an OHKO or massive damage with Foul Play. U-Turn allows Yveltal to scout and gain pressure while setting up teammates with a safe switch. Toxic allows Yveltal to cripple walls such as Lugia and Zygarde Complete. Finally Defog or Knock Off take the last slot, Defog giving team support while Knock Off just cripples some Pokemon that are dependent on an item as well as a more spammable move. None of these moves are great to lock into though so be careful to not put yourself in a position where the foe can safely set up on you.

Other Options

Offensive Choice Scarf - While there are better options such as Genesect, Yveltal can pull off a nice offensive revenge killing set quite well being either special, physical, or mixed.

Possible Partners

Primal Groudon - With the ability to check a lot of the Uber tier and being equally flexible, Primal Groudon is an excellent partner. Checking Xerneas is always a priority for Yveltal teammates, while Yveltal can check opposing Primal Groudon and Arceus fairly comfortably.
Mega Gengar - One of the best offensive partners to Yveltal, Mega Gengar can rip through the Fairies of Ubers and let Yveltal run around unchecked, while giving Yveltal pivot options with its answers such as Choice Scarfed Mewtwo.

Countering Yveltal

Fairy types - Yveltal tends to lean on its Dark STAB options and as such, Fairy types are counters to Yveltal. Xerneas can just boost on Yveltal if it doesn't switch into a Taunt and also doesn't really like Toxic, but it's mostly a free Geomancy otherwise. Arceus Fairy is another potent Pokemon that can just beat Yveltal but suffers from the same issues as Xerneas, not liking Taunt or Toxic but can break the other sets. Magearna is possibly the best option as it is immune to Toxic and only susceptible to Heat Wave, while pressuring Yveltal with Fleur Cannon or Volt Switch.
Tyranitar - Resisting all but U-Turn and the occasional Focus Blast from Yveltal, Tyranitar can pivot in fairly safely and threaten with Stone Edge, or just set up Stealth Rock to chip Yveltal on top of Sandstorm. Arceus Rock is in a similar boat, but takes neutral for Dark Pulse and Foul Play so it's slightly inferior on top of being an inferior Arceus form.

Locations in Games

Red/Blue/Yellow:
Not in game.

Gold/Silver/Crystal:
Not in game.

Ruby/Sapphire/Emerald:
Not in game.

FireRed/LeafGreen:
Not in game

Colosseum/XD:
Not in game.

Diamond/Pearl/Platinum:
Not in game.

HeartGold/SoulSilver:
Not in game.

Black/White:
Not in game.

Black 2/White 2:
Not in game.

X/Y:
Team Flare HQ (Y)
Trade from Y (X).

Omega Ruby/Alpha Sapphire:
Trade from Y

Sun/Moon:
Trade from Ultra Moon

Ultra Sun/Ultra Moon:
Ultra Space Wilds (Ultra Moon)
Trade from Ultra Moon (Ultra Sun)

Let's Go, Pikachu!/Let's Go, Eevee!:
Not in game.

Animé Appearences

Yveltal has made a few appearances in the anime. In it, it started attacking the nearby areas, turning lots of wild Pokémon and people into stone