Scovillian OHKO strat - 7-star Blastoise

=====TEAM=====
Scovillain @ Scope Lens
Ability: Insomnia
EVs: 252 SpA / 152 SpD / 104 Spe
Modest Nature
- Overheat
- Sunny Day

Espathra @ Covert Cloak
Ability: Frisk
EVs: 252 HP / 252 SpD
Calm Nature
- Lumina Crash

Manaphy
Ability: Hydration
EVs: 252 HP / 252 SpD
Calm Nature
- Tail Glow
- Heart Swap
- Helping Hand

Dedenne @ Lansat Berry
Ability: Plus
EVs: 252 HP / 252 SpD
Calm Nature
- Entrainment
- Helping Hand
- Fling
- Sunny Day

=====STRAT=====
Turn 1:
Dedenne: Entrainment on Scovillian
Manaphy: Tail Glow
Espathra: Lumina Crash on Blastoise
Scovillian: Sunny Day

Turn 2:
Dedenne: Helping Hand on Scovillian (AFTER Scovillian does Atk cheer)
Manaphy: Tail Glow
Espathra: Lumina Crash on Blastoise
Scovillian: Attack cheer

Turn 3:
Dedenne: Fling on Scovillian
Manaphy: Heart Swap on Scovillian
Espathra: Lumina Crash on Blastoise
Scovillian: wait until everything goes off, Overheat

BACKUP
If Blastoise clears itself (75% time): Manaphy does heal cheer, Espathra Lumina Crash 3 times again. If Sunny Day wears off, Dedenne sets sun again.

If Blastoise clears us (60% time): we lose probably but maybe we can reset everything up, idk lol.

=====CALCS=====
Scovillian EVed to outspeed Blastoise by one point. Everything else has max Sp. Def to tank hits better.

According to Serebii, non-Tera boosted moves into Shield do 1/5 of regular damage. Blastoise has 299 HP with a 35x HP multiplier, giving it 10,465 HP. We need to do over 5x that damage to OHKO, which is roughly 52,325 HP.

+6 252+ SpA Plus Scovillain Helping Hand Atk Cheer Overheat vs. -6 0 HP / 0- SpD Tera Steel Blastoise in Sun on a critical hit: 53220-62612 (508.5 - 598.2% of 35x hp boss) -- guaranteed OHKO

Min roll is 900 over what we need so should be OK. This also never passes the 65,536 boundary for damage overflow in case raids do something really weird and reduce the damage extremely late in the damage formula.