You possess the ability to deal with people, granting them supernatural powers and abilities in exchange for something. It can be as low as a simple rock or as high as complete and utter obedience to yourself.
You can grant someone a superpower, unlock the potential hidden within their minds, or allow them to channel magic. Your physical, mental, and spiritual strength determines how many deals you can make and how strong the abilities you grant can be. An average human could make one deal per week before they have to rest for the remainder of the week, and the power it would grant would be limited to the equivalent of 5 SP. A human with Olympic potential could make one deal per three days, and it would be limited to 10 SP and so on.
(The power you grant can either be permanent or, if you make it clear in the deal, be temporary, lasting from days to months to even years if you wish for it.)