Abilities are selectable by hotkey while on C/D. While this sounds like a simple, no big deal thing... It has gotten me killed quite a few times. I don't know what circumstances generate this, but it gets me in combat with other players. Perhaps ult is a trigger or something? No clue. 
[sg-ahri-1]
theChibiTina2 votesKayn has been bugged since his release. Riot just doesn't seem to care about him. :( Like the bug where his ult is supposed to drop turret agro, but doesn't.
High Carnifex2 votesOh. Well, that's great. I was wondering why no one ever talks about it... It gets me killed with relative frequency. Yay, Riot! Doing all the good deeds, aren't they? [slayer-jinx-unamused]
(Insert crying Kayn emoji here)