0 SpA Porygon Shadow Ball vs. +1 0 HP / 0 SpD Eviolite Misdreavus: 6-8 (27.2 - 36.3%) -- 1.1% chance to 3HKO
+1 240 SpA Misdreavus Hidden Power Fighting vs. 236 HP / 236+ SpD Eviolite Porygon: 10-12 (38.4 - 46.1%) -- guaranteed 3HKO
Porygon can break sub at +1 and eat 2 hp fight at +1, then you can play around with getting plays right with twave vs sub. But ye, I see your point.