Xenagos, the Reveler
Theros — mythic
Legendary Planeswalker — Xenagos
Xenagos, the Reveler rulings:
2013-09-15: Xenagos's first ability isn't a mana ability. It uses the stack and can be responded to. Count the number of creatures you control as the ability resolves to determine how much mana to add to your mana pool. You choose how much of that mana is red and how much is green at that time.
2013-09-15: Creature cards with bestow put onto the battlefield with the third ability will be creatures on the battlefield, not Auras.