Akali 2XKO combo: 780 damage, expert, by Katsugami. There isn’t any specific timing you need, except for the last hit of the charged 2H, where you just ne…
M > H > 2H > j.H > j.[S2] > j.66 > j.2H > j.H > j.9 > j.2H > j.H > 2H > 2 9 > j.[H] > j.[S2] > j.66 > j.H > j.S2 > j.9 > j.2H > j.[S1] > S1 > S1+S2
There isn’t any specific timing you need, except for the last hit of the charged 2H, where you just need the right timing to hit as high as possible. You really need to make sure you hit as high as possible so the charged S1 connects. Otherwise, you can shorten the S1 and release it quickly so you don’t get canceled on landing.