Oh, a Cartagia equivalent of the False Neros who kept popping up would be brilliant. And, err. It's not like in this 'verse the idea of people coming back from the dead would be unheard of. Also: Cartagia made a deal, which Londo knows. Doesn't everyone who tells Morden what they want get it? So I could see Londo, upon hearing there are rumours about Returned Cartagia, first going "thanks for giving me the laugh of the day" and then "...." mentally.