Vitiate has to gather power for his spell, where Vader has actually blitzed Jedi, dodged fire from ATT'S, moved fast enough to appear to teleport, moved fast enough to look as if he appeared out of thin air, and moved fast enough to appear as if he were in 4 places.
Vitiate has no superior or any speed feats without being on Dromund Kaas, so yeah he dies.
Vitiate doesn't have to charge his FLS. He casts it out instantly against the strike team and simultaneously charges up a powerful force blast.
His concentrated lightning is enough here, he might even get mindraped but even if Vader were able to defend against all this, Vitiate's charged blast would still demolish Vader.
He doesn't stand a chance.
Vader is a high level telepath as well, though not on Vitiates level. He casually reads Jedi minds, examples Luke and Jax, and TP tortures victims. One such victem described it as dark holes being punched in his mind, draining thought and light IIRC. Vitiate shouldn't have as easy of a time mind raping as he usually does.