The power to create supernatural weapons (a pistol that shoots out fire bullets, a light saber (literally), boots that give super speed or can fly, etc...)
I'd give myself the strongest items I make and start selling weak ones that are still stronger than military grade weapons, that way I'd control the monopoly of weapons and wars would actually be fun....
I am around the level 4 chess computer, give or take, and I don't like online chess, I heard people use the chess in their computers and play as a level 10, which is impossible to beat.