Kha'Zix Only Has Two Skins
http://imgur.com/RQwafaB Deep Terror Kha'Zix by Geruvah-Studios
Just make a skin group release giving all of the champions with barely any skins new ones. Riot seems to think that things need to be released with a theme, but I doubt that people would complain if they just created skins for champions in need of them.
is sitting at 3 other skins and that requires 2 seperate custom/varient models PER SKIN.
And to be frank, spikes being larger on shoulder for w isn't difficult, wings protruding isn't horrible to do, and bigger claws is just a slider really when it comes to creating a 3d model.
I will say the trouble is that his effects are harder to get right with each new skin, as the look between G.O.T.S. and Mecha are variable.
But I feel the reason he doesn't have many skin variants is that even with more skins, the community will still say mecha is the one and only true skin for him.