This team started out pretty bad but after a lot of fiddling it took off. There are still weaknesses but they are to uncommon threats in the metagame. I think I made the last 10+ wins of my run undefeated :)
Kyogre @ Choice Scarf
Ability: Drizzle
EVs: 4 HP / 252 SpA / 252 Spe
Modest Nature
IVs: 0 Atk
- Water Spout
- Surf
- Ice Beam
- Thunder
Probably the best Choice Scarfer in the tier. Kyogre packs enough power to revenge anything that might get past my walls. I generally try to preserve its HP since 100% Water Spout is nutcake and I might be able to set up a Kyogre sweep. In dire situations where my team is getting worn down in a stall loop I might try to switch into Kyogre for the immediate power.
Landorus-Therian (M) @ Leftovers
Ability: Intimidate
EVs: 248 HP / 252 Def / 8 Spe
Impish Nature
- Stealth Rock
- Earthquake
- Toxic
- Stone Edge
Blaziken check, Ho Oh check, Zekrom check, SR user, can also do something against stuff like Kangaskhan and EKiller. Unfortunately it is easily set up on. I can't stop EKiller from using second Swords Dance or Kangaskhan from using Power Up Punch. It doesn't hit hard enough but it needs all the bulk it can get to hold up to Ho Oh which is crazily strong and who the rest of my team has trouble handling.
Blissey (F) @ Leftovers
Ability: Natural Cure
EVs: 252 Def / 252 SpD / 4 Spe
Calm Nature
IVs: 0 Atk
- Flamethrower
- Soft-Boiled
- Toxic
- Heal Bell
Primary special wall, acts as my cleric as well. Cleric is needed since my Pokemon are rather susceptible to status (Ferrothorn attracts burn like honey attracts bees, Landorus does the same with poison). Flamethrower is there not because of Mega Gengar but because of Ferrothorn, which my team really hates. Also kills Scizor and Genesect which can be helpful, Genesect loves to pivot on Blissey. I really wish I could have Wish on Blissey since Landorus, Kyogre and to some extent Ferrothorn could really use it. On the other hand having Wish without Protect really weakens Blissey as a Xerneas check.
Ferrothorn @ Leftovers
Ability: Iron Barbs
EVs: 252 HP / 4 Def / 252 SpD
Careful Nature
- Power Whip
- Spikes
- Toxic
- Leech Seed
Mandatory Water resist. I originally tried to rely on Blissey for everything but the Kyogre weakness was too real. In the end I added Ferrothorn because my team was having serious trouble against Ferrothorn, and I figured if I can't beat them join them. Primarily meant to check Kyogre but can also wear down things like Xerneas (without HP Fire) and Blissey / Giratina etc. Absorbs Leech Seed as well. Spikes are also helpful to help my team outstall my opponent. I have Power Whip because otherwise I have trouble against CM Refresh Water Arceus, I didn't meet any though. Not having Gyro Ball weakens me to Skymin and to some extent Xerneas but what to do?
Yveltal @ Leftovers
Ability: Dark Aura
EVs: 248 HP / 252 Def / 8 Spe
Impish Nature
- Foul Play
- Taunt
- Roost
- Sucker Punch
Mandatory EKiller check. Sucker Punch to kill Mewtwo Y. Taunt to help break stall and so that Yveltal isn't set up bait (i.e. Ferrothorn). One problem with Yveltal is that it's my main EKiller counter as well as my main Mewtwo counter, which can potentially stress it out especially if Mewtwo has Ice Beam. I had one game where I had to Roost with my 6% Yveltal against a Xerneas, risking his Moonblast (he used Geo), then sacrificing another Pokemon to Xerneas just so Yveltal could take on Arceus later. I won the game, but it feels like my opponent misplayed.
Scizor @ Scizorite
Ability: Light Metal
EVs: 252 HP / 16 Atk / 240 SpD
Adamant Nature
- Roost
- Bullet Punch
- Superpower
- Defog
My Defogger, as well as a Xerneas check which the specially defensive spread helps with. Retains enough attack to 2HKO most Xerneas with Bullet Punch. Superpower is there to help with Ferrothorn, which like I wrote before I am really weak to. After I put Superpower on Scizor, Taunt on Yveltal and Flamethrower on Blissey, it finally got manageable.
In my experience the main threats are:
Ho Oh: Landorus is about as good a Ho Oh check as they come but with Ho Oh having such staying power it can outlast Landorus. Doesn't help either that burned Landorus can't OHKO Ho Oh with Stone Edge.
Deoxys S: It gets up two layers unless I Taunt it with Yveltal, when it would still be at 100% and can switch out. Sucks.
Kyogre: I have no safe switch in for Specs Water Spout if he's at 100%. So if I see a Kyogre in team preview I lead with my own Kyogre, hoping to attack his Kyogre before he kills me.
Xerneas: I have two semi-reliable Xerneas checks and usually bring in whichever looks like the more expendable one. On the other hand it could potentially Sub against Blissey and make me cry. GeoXern with HP Fire plus Psyshock or Focus Blast if it hits twice or if Toxic misses sweeps me.
Mewtwo and Deoxys A with Ice Beam: never really met them but if they predict the Yveltal coming in I pretty much have to resort to revenge killing.
It's possible there are more uncommon threats that I never met.
Comments appreciated!

Kyogre @ Choice Scarf
Ability: Drizzle
EVs: 4 HP / 252 SpA / 252 Spe
Modest Nature
IVs: 0 Atk
- Water Spout
- Surf
- Ice Beam
- Thunder
Probably the best Choice Scarfer in the tier. Kyogre packs enough power to revenge anything that might get past my walls. I generally try to preserve its HP since 100% Water Spout is nutcake and I might be able to set up a Kyogre sweep. In dire situations where my team is getting worn down in a stall loop I might try to switch into Kyogre for the immediate power.

Landorus-Therian (M) @ Leftovers
Ability: Intimidate
EVs: 248 HP / 252 Def / 8 Spe
Impish Nature
- Stealth Rock
- Earthquake
- Toxic
- Stone Edge
Blaziken check, Ho Oh check, Zekrom check, SR user, can also do something against stuff like Kangaskhan and EKiller. Unfortunately it is easily set up on. I can't stop EKiller from using second Swords Dance or Kangaskhan from using Power Up Punch. It doesn't hit hard enough but it needs all the bulk it can get to hold up to Ho Oh which is crazily strong and who the rest of my team has trouble handling.

Blissey (F) @ Leftovers
Ability: Natural Cure
EVs: 252 Def / 252 SpD / 4 Spe
Calm Nature
IVs: 0 Atk
- Flamethrower
- Soft-Boiled
- Toxic
- Heal Bell
Primary special wall, acts as my cleric as well. Cleric is needed since my Pokemon are rather susceptible to status (Ferrothorn attracts burn like honey attracts bees, Landorus does the same with poison). Flamethrower is there not because of Mega Gengar but because of Ferrothorn, which my team really hates. Also kills Scizor and Genesect which can be helpful, Genesect loves to pivot on Blissey. I really wish I could have Wish on Blissey since Landorus, Kyogre and to some extent Ferrothorn could really use it. On the other hand having Wish without Protect really weakens Blissey as a Xerneas check.

Ferrothorn @ Leftovers
Ability: Iron Barbs
EVs: 252 HP / 4 Def / 252 SpD
Careful Nature
- Power Whip
- Spikes
- Toxic
- Leech Seed
Mandatory Water resist. I originally tried to rely on Blissey for everything but the Kyogre weakness was too real. In the end I added Ferrothorn because my team was having serious trouble against Ferrothorn, and I figured if I can't beat them join them. Primarily meant to check Kyogre but can also wear down things like Xerneas (without HP Fire) and Blissey / Giratina etc. Absorbs Leech Seed as well. Spikes are also helpful to help my team outstall my opponent. I have Power Whip because otherwise I have trouble against CM Refresh Water Arceus, I didn't meet any though. Not having Gyro Ball weakens me to Skymin and to some extent Xerneas but what to do?

Yveltal @ Leftovers
Ability: Dark Aura
EVs: 248 HP / 252 Def / 8 Spe
Impish Nature
- Foul Play
- Taunt
- Roost
- Sucker Punch
Mandatory EKiller check. Sucker Punch to kill Mewtwo Y. Taunt to help break stall and so that Yveltal isn't set up bait (i.e. Ferrothorn). One problem with Yveltal is that it's my main EKiller counter as well as my main Mewtwo counter, which can potentially stress it out especially if Mewtwo has Ice Beam. I had one game where I had to Roost with my 6% Yveltal against a Xerneas, risking his Moonblast (he used Geo), then sacrificing another Pokemon to Xerneas just so Yveltal could take on Arceus later. I won the game, but it feels like my opponent misplayed.

Scizor @ Scizorite
Ability: Light Metal
EVs: 252 HP / 16 Atk / 240 SpD
Adamant Nature
- Roost
- Bullet Punch
- Superpower
- Defog
My Defogger, as well as a Xerneas check which the specially defensive spread helps with. Retains enough attack to 2HKO most Xerneas with Bullet Punch. Superpower is there to help with Ferrothorn, which like I wrote before I am really weak to. After I put Superpower on Scizor, Taunt on Yveltal and Flamethrower on Blissey, it finally got manageable.
In my experience the main threats are:
Ho Oh: Landorus is about as good a Ho Oh check as they come but with Ho Oh having such staying power it can outlast Landorus. Doesn't help either that burned Landorus can't OHKO Ho Oh with Stone Edge.
Deoxys S: It gets up two layers unless I Taunt it with Yveltal, when it would still be at 100% and can switch out. Sucks.
Kyogre: I have no safe switch in for Specs Water Spout if he's at 100%. So if I see a Kyogre in team preview I lead with my own Kyogre, hoping to attack his Kyogre before he kills me.
Xerneas: I have two semi-reliable Xerneas checks and usually bring in whichever looks like the more expendable one. On the other hand it could potentially Sub against Blissey and make me cry. GeoXern with HP Fire plus Psyshock or Focus Blast if it hits twice or if Toxic misses sweeps me.
Mewtwo and Deoxys A with Ice Beam: never really met them but if they predict the Yveltal coming in I pretty much have to resort to revenge killing.
It's possible there are more uncommon threats that I never met.
Comments appreciated!