"The usual: ownership of your soul. Part of it, at least. Enough to claim it after you die or exert influence if I really wanted to. Which I don't. Again, lesson learned from my Alastor. And since you're a powerful demon, it gives me access to some of your power while you access some of mine."

Despite the severity of the cost, Dante waves a hand. "It's kinda necessary. That said, I'll let you decide the terms of when I can do that. Least I can do."