Separator Keys - They separate your keycount into separate signs:
Positive
World 6 spoilers: Artngvir
World 11 spoilers: naq gurve Vzntvanel inevnagf.
This is a toggle-on toggle-off effect.
This would finally make these cbfvgvir-artngvir Pbzob Qbbef openable! (W9 spoilers)
Upon touching an Unseparator Key, your total key amount of that colour will be set to all of the keys added together.
World 11 spoilers: Sbe rknzcyr, vs lbh unq 3, -2, 4v, naq -1v Checyr Xrlf, hcba gbhpuvat na Hafrcnengbe lbh jbhyq raq hc jvgu 1 + 3v Checyr Xrlf (3 - 2 + 4v - 1v).