Yasuo 2XKO combo: 461 damage, easy, by Evan Almighty. Side swap by doing [6S1] instead of the dash up S2 - 442 damage
6T > T > H > 2S1 > M > j.S2 > 6[S1] > 2S1 > M > j.2H > j.S2 > 2S1 > 2H > 2S1 > 6 > dl.S2 > 2S1 > M > j.2H > j.S1 > j.S1 > j.S2
Side swap by doing [6S1] instead of the dash up S2 - 442 damage