Personally I have little interest in using the Incubus at all. I like the Succubus just fine. And I almost never use them anyway.
Warlocks used to use them for CC back in the day. When people used CC. And we can use them in PvP. But I don’t do that often. I haven’t summoned my Succubus other than to take a screen shot once maybe a year ago.
The Voidwalker I use when I am alone. The imp I use when I am in groups in PvE. I might use the observer if I can’t trust anyone to interrupt. But it’s really just the Voidwalker and Imp.
If I was any good at PvP, I would use the Incubus on Males - because there are Conservative Right Wingers who might unplug their computers before watching their avatars be seduced by a male demon lol