Okay I want a rexwalker/rexvader AU where Vader goes back in time and kidnaps Rex.
Like Rex is probably leading a scouting mission or something. Vader manages to separate Rex from the group, puts him in a Force induced sleep and carries him away to an awaiting ship.
Jesse is the first of the group to notice Rex is missing. They don't find their captain but they do find his helmet and twin blaster pistols. This is very bad because Rex wouldn't go anywhere without these items so the group books it back to base to alert their COs. But Anakin is away with Obi-Wan on negotiation talks so the only COs there are Ahsoka and Cody. Cody immediately starts gathering a search party. And oh no the generals come back earlier than expected so now Anakin, already annoyed with how poorly negotiations went, absolutely loses it when they tell him they lost Rex.
Meanwhile Rex is on a strange ship with Old Man Yularen giving him a look of disbelief because he just saw the man not that long ago and didn't look this old. Vader then brings Rex to his private quarters, explains everything (kinda) to him and even removes his helmet for a bit. Oh and that breaks Rex because how could this happen to his general. So when Vader asks Rex to stay he does because it just pains him too much to leave his Jedi like this.
Shit will go down once Anakin and Vader meet though and Rex will have to choose.
