possible kayn bugs
it may just be in hectic fights but I'm quite certain when I hit a 5 man w that gives me the pick of whom I ult. but in most cases I'll spam it on them and it'll be all "oh you have to damage them first" and I'm just sitting wondering why I wouldn't have damaged the 300 health twitch that I solo engaged the tower banking on being able to ult AND FOR THAT PURPOSE ALONE
lucky me his e only takes about a second after pressing to realise I can path through walls and stops running me around them while I waste time being invincible for no reason.