So, this is what just happened:
Looked for battle on PS (battle spot singles tier)
the battle starts
I picked Manectric and the other guy strangely enough picked Cottonee
I mega evolve and use flamethrower
Cottonee is alive with 34% HP
So I made my calcs to see if that's even possible, and...
252 SpA Manectric Flamethrower vs. 252 HP / 252 SpD Eviolite Cottonee: 600-708 (2608.6 - 3078.2%) -- guaranteed OHKO
Sorry but couldn't get a screen or battle link
Looked for battle on PS (battle spot singles tier)
the battle starts
I picked Manectric and the other guy strangely enough picked Cottonee
I mega evolve and use flamethrower
Cottonee is alive with 34% HP
So I made my calcs to see if that's even possible, and...
252 SpA Manectric Flamethrower vs. 252 HP / 252 SpD Eviolite Cottonee: 600-708 (2608.6 - 3078.2%) -- guaranteed OHKO
Sorry but couldn't get a screen or battle link