>>19744799>subbing against dual crunchesNot saying the second would be able to kill on its own, but certainly after Perish Song he'd be weakened enough.
In any case, it's not about which is better assuming one-on-one, it's about which is simply better overall. And it's absolutely M-Gengar. M-Kang's biggest assets are breaking though subs with absolutely no issue and 2HKOing nearly anything that isn't a ghost with Seismic Toss. But an over-reliance on contact moves and base 100 speed are its biggest downfall. There aren't many true counters, but basically anything that fucks over contact move users (Ferrothorn, anything with Flame Body/Static, and Cofagrigus come to mind) can most likely switch into an attack and cause more trouble for Kangaskhan than the damage they received.
M-Gengar however has no counters. M-Gengar has a much greater movepool, obviously, and can even fuck over almost every Soundproof user with Shadow Ball or Focus Blast. He's frail as hell by Ubers standards, but he's fast enough to only need one turn of Perish Song. Just one turn. That's all he needs.
252 Atk Teravolt Zekrom Bolt Strike vs. 252 HP / 0 Def Mega Gengar: 285-336 (87.9 - 103.7%) -- 25% chance to OHKO
+2 252+ SpA Fairy Aura Xerneas Moonblast vs. 252 HP / 0 SpD Mega Gengar: 239-282 (73.7 - 87%) -- guaranteed 2HKO
And he will get that turn.
