So after spending 2 hours trying to catch the sixline out of the sump (kept jumping from one chamber to the next) I finally caught the little bugger
ended up putting him in the fowlr tank. So far so good, he hid for a bit, but then started checking out his new home. Also hasn't showed any interest in the cleaner wrasse and the other fish don't seem to care about him being in there, here's hoping it stays that way and no one decides the carpet looks like a better place to be.