Magic The Gathering Cards of types 'Rebel' and 'artifact'

At the beginning of your upkeep, put a random card from outside the game into your hand. (In Commander sealed, that's everything you didn't play with. In any other commander game, find a way to select a random Magic card.) {T}: Add {W}{U}{B}{R}{G}. This mana can't be spent to pay generic mana costs.