mtg vault cards Mana none) open.class The Key to the Vault

If cascade allows you to cast a split card, you may cast either half but not both halves.

A creature like Uro immediately made me think about the Evoke keyword

Second, the player with the initiative ventures into Undercity again at the beginning of their upkeep

Will Scourge of the Skyclaves die, because it doesn't have the ability and is a 0/0 or does it immediately becomes a 1/1 to stay alive

They can wield equipment

To determine the total cost of a spell, start with the mana cost or alternative cost you're paying (such as a flashback cost), add any cost increases (such as kicker costs), then apply any cost reductions (such as that of The Water Crystal's first ability)