Considering the thought of breaking succubus into being waifus is amongst the top tier plots for me likely the same.
Speaking of breaking aggressive characters.... maybe a female officer of the elite faction or one of their ruling council when she visits planetside (saving her from bandits, then takes her himself to "protect her") as a content idea for later on.
Make her be a switch to appeal to people who like "mommy dom" or pet/etc (Making her be unable to be a floor one for MC exclusive use as a wrinkle in it, possibly MC thinking that'd guarantee he's dead no matter what she agrees to) would be legit. Inb4 first actually thicc/MILF type character.