Seekom Evolves to Darkom
(Seek + Comet, as a hint to tell players how to evolve it. Dark + Comet for it's new type & what caused it to evolve.)
Maybe Lightkom or Lykom for the first stage? (Light to contrast Dark.)
Tokala & Kitsula sound good.
So you lie the second name, but it sounds too similar to another Pokémon? Ok. And no comet reference? Let's work with that.
Ah.... Perhaps it should be Lyfo? Lyox? Lyfox?