Igglybuff OHKO strat - 7-star Charizard

=====TEAM=====
Igglybuff @ Focus Sash
Ability: Friend Guard
EVs: 252 Atk / 252 Spe
Adamant Nature
- Play Rough
- Psych Up

Magmar @ Eviolite
EVs: 252 HP / 252 SpD
Calm Nature
- Belly Drum
- Scary Face

Swampert @ Zoom Lens
EVs: 252 HP / 252 SpD
Sassy Nature
IVs: 0 Spe
- Screech

Florges (F) @ Pixie Plate
Ability: Symbiosis
EVs: 252 HP / 252 SpD
Calm Nature
- Helping Hand

=====STRAT=====
If Overheat hits Igglybuff turn 0, we lose

Turn 1:
Swampert: Screech on Charizard
Florges: Attack cheer
Magmar: Belly Drum
Igglybuff: Psych Up on Magmar (must wait until after Belly Drum)

Turn 2:
Swampert: Screech on Charizard
Florges: Helping Hand on Igglybuff
Magmar: Scary Face
Igglybuff: nothing

Turn 3:
Swampert: Screech on Charizard
Florges: nothing
Magmar: nothing
Igglybuff: wait for everything to go off then Play Rough

IF Charizard misses Igglybuff turn 1, just spam Heal Cheer until it hits Igglybuff

=====CALCS=====
+6 252+ Atk Pixie Plate Igglybuff Helping Hand Atk Cheer Play Rough vs. -6 0 HP / 0 Def Tera Dragon Charizard: 7548-8882 (101.6 - 119.6% of 25x hp boss) -- guaranteed OHKO

Magmar survives Belly Drum + Overheat + Hurricane + Hurricane with Friend Guard. Survives Overheat + 2 Hurricane 93% of the time.

0+ SpA Tera Dragon Charizard Hurricane vs. 252 HP / 252+ SpD Eviolite Magmar with 1 ally's Friend Guard: 57-67 (17 - 20%) -- possible 5HKO
0+ SpA Tera Dragon Charizard Overheat vs. 252 HP / 252+ SpD Eviolite Magmar with 1 ally's Friend Guard: 33-39 (9.8 - 11.6%) -- possible 9HKO

Swampert survives Overheat + 3 Hurricanes with Friend Guard.
0+ SpA Tera Dragon Charizard Hurricane vs. 252 HP / 252+ SpD Swampert with 1 ally's Friend Guard: 82-97 (20.2 - 24%) -- guaranteed 5HKO
0+ SpA Tera Dragon Charizard Overheat vs. 252 HP / 252+ SpD Swampert with 1 ally's Friend Guard: 47-56 (11.6 - 13.8%) -- possible 8HKO