As much as I hate this character, he can stay.
Duncan is and always has been an anti-hero, and we have plenty of those in the wiki. He was a main protagonist in Island, THE main protagonist in Action, a minor hero in All-Stars, and while his actions in World Tour have been sketchy he was never portrayed as an all-out villain either, especially compared to a good half of the remaining cast at the time. If characters like Deadpool, Bender and Bowser can be on this page despite clearly not always being heroic characters in the series they're featured in, then I see no reason for this character to be excluded when, from a storytelling perspective, he's always been more of a hero than not.
I hate this character very much
Whoever is putting false middle/surnames, STOP IT![]
Duncan's middle name and surname were never revealed!