Board Thread:Questions and Answers/@comment-5618861-20160815190434/@comment-29325824-20160815204202

Well, their stamina, lust, and "capacity" improve greatly to keep up with their wife but that's about it. Repeated sex might increase the amount of Spirit Energy their body produces, and therefore their magical skills, but I doubt they'll ever reach Hulk levels of power.

Likewise, what kind of Incubus they are also depends on their wife. A Mamono that's pretty normal and very low maintenance, like a Kobold, Kikimora, or Holstaur, will have no effect. But for example a Lava Golem's husband becomes heat resistant; a Giant Ant's husband can see better in the dark underground; and a Undead's husband becomes immune to the poison of an "Undead Mushroom"(?).