I hereby offer Ezreal, Kassadin and Ryze as a void exploration team. As far as nobody knows the Void better than Kassadin, he would be a good guide, and Ezreal have the exploring skills and experience needed for it. Also, Ryze should be learning more, more, more, more and more about magic at Runeterra, but once in void, his possibilites could be infinite. Another champion that *possibly* would take part in a void Exploration team would be Garen, if many Voidling Spawns got to Demacia. Like a Voidling invasion forces him to enter there. But that would make a complete lore change, and as far as im concerned, RIOT should be preparing something tematic as a Void invasion that would unify Ionia, Noxus and Demacia against the Void.
Also, after Ionia vs Noxus match, i would love to see a Void ( Maw, Cho'Gath and Malz ) against the three generals of Runeterra army ( Garen, Swain and Irelia ).
About Skins: Darkside Ryze, Mad Explorer Ezreal and Guide Kassadin.
Hope i added something! ;D
@Cidem1324 -- Ty, just corrected the issue about Katarina/Swain