252 Atk burned Drapion Knock Off (97.5 BP) vs. 176 HP / 0 Def Sigilyph: 148-175 (44.9 - 53.1%)
0 SpA Seismitoad Hydro Pump vs. 176 HP / 0 SpD Sigilyph: 126-148 (38.2 - 44.9%)
you'd have to be pretty bulky to tank Megalix's earthquake for 40%;
252+ Atk Mega Steelix Earthquake vs. 252 HP / 252+ Def Seismitoad: 151-178 (36.4 - 42.9%)