Counter that Pokémon! SM v.2

Tapu Lele @ Choice Specs
Ability: Psychic Surge
EVs: 252 SpA / 4 SpD / 252 Spe
Timid Nature
- Psychic
- Moonblast
- Psyshock
- Hidden Power Fire

Jirachi @Choice Scarf
EVs: 252 Atk / 4 SpD / 252 Spe
Ability: Serene Grace
Jolly Nature
-Iron Head
-U-Turn
-Healing Wish
-Fire Punch

Survives HP Fire then outspeeds and OHKOs with Iron Head.

Heatran @ Leftovers
Ability: Flash Fire
EVs: 252 HP / 4 SpD / 252 Spe
Timid Nature
IVs: 0 Atk
- Toxic
- Substitute
- Magma Storm
- Earth Power

Keldeo @Choice Specs
Ability: Justified
EVs: 252 SpA / 4 SpD / 252 Spe
Timid nature
- Scald
- Hydro Pump
- Secret Sword
- Hidden Power [Electric]

what's up it's your favourite pony doing what it does best: forcing heatran out

Venusaur @ Venusaurite
Ability: Chlorophyll
EVs: 248 HP / 88 Def / 156 SpD / 16 Spe
Calm Nature
- Giga Drain
- Sludge Bomb
- Synthesis
- Hidden Power Fire

Mesprit @Assault Vest
EVs: 4 HP / 252 SpA / 252 SpD
Ability: Levitate
Sassy Nature
-Psyshock
-Dazzling Gleam
-Ice Beam
-Thunderbolt

Tanks any of Venu's attacks and 2HKOs with Psyshock

Weavile @ Choice Band
Ability: Pressure
EVs: 252 Atk / 4 SpD / 252 Spe
Jolly Nature
- Icicle Crash
- Knock Off
- Ice Shard
- Pursuit

Tanks a Dazzling Gleam well and then OHKOs with Knock Off.

Poliwrath @ Leftovers
Ability: Water Absorb
EVs: 252 HP / 252 Atk / 4 SpD
Relaxed nature
-Rest
-Sleep Talk
-Scald
-Circle Throw

First Knock Off hits around 21.8 - 25.7% if it chooses to lock itself in that (more hits does 17.1% at most if there are no crits) and Icicle Crash is only a possible 5HKO. Meanwhile, Circle Throw instantly KOs.

Jellicent @ Leftovers
Ability: Water Absorb
EVs: 252 HP / 4 SpA / 252 Spe
Timid Nature
- Taunt
- Toxic
- Scald
- Hex

Hydreigon @ Choice Scarf
Ability: Levitate
EVs: 252 SpA / 4 SpD / 252 Spe
Timid Nature
- Dark Pulse
- Draco Meteor
- Fire Blast
- U-turn

Sylveon @ Life Orb
Ability; Pixilate
EVs: 252 Atk / 252 Spe / 4 SpA
Hasty Nature
-Return
-Quick Attack
-Bite
-Hidden Power Ground

Crobat @ Life Orb
Ability: Infiltrator
EVs: 252 SpA / 4 SpD / 252 Spe
Timid Nature
- Sludge Bomb
- Heat Wave
- Nasty Plot
- Hidden Power Ground

Quagsire @ Lefties
Ability: Unaware
Evs: 252/ HP+SpD
Bold Nature
- Scald
- Ice Beam
- Recover
- Toxic

Tapu Bulu @ Choice Band
Ability: Grassy Surge
EVs: 252 Atk / 4 Def / 252 Spe
Adamant Nature
- Wood Hammer
- Horn Leech
- Superpower
- Zen Headbutt

Silvally-Poison @ Poison Memory
Ability: RKS System
EVs: 252 Atk / 4 SpD / 252 Spe
Adamant Nature
- Multi-Attack
- Flame Charge
- Swords Dance
- Ice Fang
Will outspeed and KO Bulu

Whiscash @ Flyinium Z
Ability: Oblivious
EVs: 252 Atk / 4 SpD / 252 Spe
Jolly Nature
- Dragon Dance
- Earthquake
- Waterfall
- Bounce

Rotom-Mow @ Grassium Z
Ability: Levitate
EVs: 4 Def / 252 SpA / 252 Spe
Timid Nature
- Volt Switch
- Leaf Storm
- Thunderbolt
- Will-O-Wisp

Rotom OHKOs with Leaf Storm and Whiscash needs to set up twice to 2HKO. Bring it on.

Turtonator @White Herb
Ability: Shell Armour
EVs: 252 SpA / 4 SpD / 252 Spe
Timid Nature
-Shell Smash
-Fire Blast
-Dragon Pulse
-Draco Meteor

Easily survives all the offensive moves, even Bloom Doom, and is immune to Will-o-Wisp. OHKOs with Fire Blast.

Tapu Fini @ Leftovers
Ability: Misty Surge
EVs: 248 HP / 236 Spe / 24 SpA
Timid Nature
-Calm Mind
-Hydro Pump
-Moonblast
-Taunt

+2 252 SpA Turtonator Fire Blast vs. 248 HP / 0 SpD Tapu Fini: 112-132 (32.6 - 38.4%) -- 4.1% chance to 3HKO after Leftovers recovery
24 SpA Tapu Fini Hydro Pump vs. 0 HP / 4 SpD Turtonator: 133-157 (50.9 - 60.1%) -- guaranteed 2HKO

Kyurem-Black @ Life Orb
Ability: Teravolt
EVs: 252 Atk / 4 SpA / 252 Spe
Naive Nature
- Freeze Shock
- Fusion Bolt
- Ice Beam
- Earth Power

Man, how come my Tapu Fini is never this tenacious? Took forever to find something to come anywhere near to OHKO.