If this means, 'did good work as an Avenger', then causing trouble and being a tag along would sort of cover it - at least in the early days. In my opinion, the entire issue where she marries the Swordsman is laugh out loud funny and I don't think it was intended to be. Over in WCA, Mantis (or a reasonable simulation) caused trouble once again and nearly killed everyone in her first appearance. I liked that though and would have liked her to stick around. If this means, 'made the books better', well... the early rendition is a bit racist to a modern reader, I suppose, but normal for the era. Some fun was had and it was nice to see a different female member of the cast. Outside, Avengers? I never read the pre-Bendis Guardians, but I liked Mantis in Silver Surfer and in her very recent Guardians appearance. Bendis can give a character two pages and make me love them. I would like to see her back with the Avengers. As for the movie - the actor could have been portraying a character other than Mantis and it wouldn't have made any difference. This wasn't Mantis exactly as we tend to see her: Celestial Madonna, skilled fighter, temptress... although this did capture some of the innocence we often got with this character. Kind of surprised the sequel went with a slave female character, when it had come in for some criticism of the female slaves under The Collector's control.