>>384447640- Atk Sceptile-Mega Rock Slide vs. 0 HP / 4 Def Charizard-Mega-Y: 260-308 (87.5 - 103.7%) -- 18.8% chance to OHKO
It is a 1/5 win rate in charizard's favour
Also, both flamethrower (under the sun) and air slash kill scept in a single move