This game still lacks a Voodoo-based Champion
World of Warcraft has been going strong with its version of Voodoo (just look at the Zandalar scene), yet there are no Champions in the roster right now who utilize it, or at least something that's Voodoo in all but name. It'd be awesome if we got something like an expy (of sorts) of Baron Samedi, the Voodoo god of death and reincarnation, but any Champion who uses Voodoo would be good.
Of course, it doesn't have to be called Voodoo in Runeterra, but it should at least be Voodoo in all but name.
EDIT: I am fully aware of Tabu, who got cancelled during League's beta phase.
. We don't have that much on them other than just Illaoi though, but it was mentioned by a Rioter to be inspired by Mayan and Polynesian culture.