Pacts.

(I am most defiantly not mega wise when it comes to this topic. So please. Feel free to correct me.)

Pacts are basically deals that you make with a supernatural being or anything else. (I.e. you can make a pact with a cheetah to get its speed but you would have to give up the thing that is most valuable to you.) The thing with Pacts are that you have to trade the thing that is most valuable to you to complete the Pact. (I.e. if Shadow made a pact with a cat, he would get the cats agility, balance and stealth, but he would give up his sight or his strength.) Pacts can be made with anything. Personally I know someone that made a pact with the golden bird god card from You-Gi-Ho! (forgot its name). Hope I didn't confuse you too much.