These are the 13 best blue creatures in Magic: The Gathering and how to use them. ... It only costs one blue mana to cast, so it can make an impact right away if you can transform it.

The bad news is that Mana Vault is only legal in Commander, where it's on the list of Game Changer cards, and it's restricted in Vintage. Still, if you want to get your hands on one, there are ...

For example, a card costing could be paid with a blue or a black mana. While we can’t make out the images (This is likely intentional), they appear to be the Game Day Return to Ravnica promo cards.