Kids on Bikes RPG: Powered Character Deck - Rules of Play says:
Kids on Bikes features a Powered Character Deck, which introduces Traits for a powerful character co-controlled by all of the players at the table. Using aspects of the character from the GM, players will share narrative control over what the character does - and when they use their mysterious, dangerous powers! Players will more than likely need their powers to get you out of a pinch, and as you play more, the powered character will get stronger and stronger!