maw of the multiverse

maw of the multiverse deals X damage to all opposing creatures and players during your upkeep, each creacure killed this way's mana cost is put into your mana pool, but can only be used to play natural effects. all instant's and sorcery's are countered. planeswalkers can not activate there ultimate ability.
Ones it's here theres no stoping it. we will all be reverted to mana!
- Elgeran mon shald, professor at the Elgom University for the gifted, a multiverse specialist.