Perfect example of this is the movie Dogma. Kevin Smith has stated he would love to do a follow up on it, but he as the creator can’t because the IP is owned personally by Harvey Weinstein, and he refuses to give money to Harvey to license or buy it because obvious reasons. So, his own creation is locked away from him because a monster put up the money for the original before Kevin or most people knew they were a monster.
Playing Descent II online was one of the highlights of my childhood back in the early days of internet gaming. The community was excellent too, with a lot of custom maps created using the D2 Level Builder, which I got pretty good with myself haha.