Karthus' Cooldown Clocks [GAMEPLAY]
On ARAM, when Karthus dies, his cooldown circles (how much of it is covered) reset, winding down with the actual cooldown. So if I had 30 seconds left on my ult cooldown, then died, the circle would be reset to full but would pass at the right rate to be done in 30 seconds. I'm not sure if I explained this well, and it's not super game-breaking, but it's worth noting.