I should have remembered Andeddu. Especially since I named my Sorceror after him.
There is Darth Andeddu, but he seems to be an isolated case. There is a theory that Darth is comes from the Rakatan "darr tah" = "triumph over death". So it makes sense that the Andeddu who lived very long through essence transfer would choos it as personal title without making it a common title.