Pazzo, you need to be more nice to a succubus or else she might hurt you...and I'm not talking about the good type of pain which you get from your mistress while she is punishing you.
So you have problems with stealing souls? That's kinda easy, just seduce someone and then suck their soul out of their body. If you can't seduce others, then use something else like your cuteness to lure people into your trap.