mtg commander bear deck / EDH decks — Bear Deck Box Mtg -

Mana Vault Description : Mana Vault is an artifact that taps for three colourless mana, but it comes into play tapped and requires paying four mana during each upkeep or untap step, or else it deals one damage to its controller

Rather, a second "reflexive" ability triggers when you sacrifice Eden, Seat of the Sanctum this way

Gramma Tala Spirit of the Ocean Heres a card I bet you didnt see coming a Floodborn Gramma Tala

That said, it's not clear who put the item up for auction, or if it was even one of the original recipients

It comes down early and powers out your key creatures then serves as a value engine later on when things get grindy