Arylkor, Apex of Power

Flying, Vigilance, Indestructible, Trample
Arylkor, Apex of Power costs {1} less to cast for
each nonland permanent you control with
converted mana cost 3 or greater.
Arylkor, Apex of Power's mana cost cannot be
altered by sources other than Arylkor's abilities.
When Arylkor enters the battlefield, if it wasn't
cast, you lose the game.