Camille E can hit invisible targets (kha zix)

It will 100% hit kha'zix while he's stealthed. He isn't untargetable like Yi q.

Yeah, and honestly, the more counterplay to stealth, the better, as stealth itself is one of the most BROKEN mechanics in game for any champion that is even moderately strong. Just look at when twitch was good: shows up from stealth during a 15(?) second long stealth mode to be able to gain optimal positioning and blow up the enemy team in about 2-3 seconds max.

Or look at vayne and kai, or our wonderfully latest broken champ, shaco, with his recent changes.

All skillshots can hit invisible targets. Camille e is a skillshot. Not a bug, nor is it possible in tft as camille no longer exists in tft.