So when's the next Karthus skin?

Look, I know it may seem like a bit of bias because I'm a karthus main (it probably is), but I would really like to see a new Karthus skin. ESPECIALLY a new one with some actual change to his particle effects! Karthus hasn't had a REAL skin in a good while (Sorry, but I refuse to count the FNATIC skin since it's only commemorating FNATIC's win in S1.), and even though he's been updated last year, he hasn't really had anything to show for it. (his skin splash screens aren't helping my case either, but that's another post)

Some of my personal ideas for skins, and my reason for them.

Pharaoh Karthus - Come on, Riot's been doing a lot of Shruima based skins recently, and karthus just sort of fits in this area!

Full Metal/Mecha Karthus - This is mostly because I love machine skins and I really want one for Karthus :P (reason I'm not suggesting Battlecast is because it's already kind of weird having a battlecast Xerath and Battlecast themed Viktor on the same side.)

Ringleader Karthus - I actually did a post on this particular skin. It just seems like a cool concept. Maybe pair him with Shaco or something. (Link to article: http://boards.na.leagueoflegends.com/en/c/skin-champion-concepts/Om7gaEph-ringmaster-karthus-skin-idea)

Voidborn Karthus - Somewhat of a weird idea, but I don't think I would have thought of Voidborn Nocturne either.

What are your thoughts on a new Karthus skin? What do you think of the ideas that I came up with? How would he look like with those new Chroma skins that Riot is currently showcasing?