Animation cancelling is what takes a mediocre champ like Renekton and makes him absolutely busted. Just look at this clip of T1 Zeus. After building up 50 Rage to prepare for his combo, he fans going back to his turret to recall, but actually loops back to the bush to chase Swain. Not expecting this, Swain gets just barely in range of the bush, and that's all Zeus needs. Now pay close attention to how cleanly he bursts down his target. That was pretty fast, right? Let's break it down. He exits the bush with E to close the gap, Autos then uses his empowered W to cancel that auto animation. This instantly procs press the attack and bork. Renekton's W has a decently long animation that locks him in place, but he uses his ult to cancel that animation as well. This frees him up to land another auto attack, the second part of his E and an empowered Q. Just one more auto and ignites to cures the kill on a target with 2000 HP and an instant. So you can see why