[CHAMPION-QUINN] Ult on Respawn
So when you respawn as Quinn when you've learned your ult, you start out with Valor carrying you, but can't cast Skystrike. Instead, the ult is replaced with Cancel Channel, and when used, Skystrike doesn't cast and the ult just ends.
Happened during the game and in the practice tool, so it seems pretty consistent that it happens. It may be a rune interaction or something, though, since I've not seen it on here. Also remember reading somewhere that this might not be a bug, but a change they wanted to make.