Late this spring, we identified that Force of Will / Mana Drain decks were winning in Vintage much more consistently than the other three kinds of decks. One cause of this was the removal of power-level errata on Time Vault. That card combined with either Voltaic Key or Tezzeret the Seeker now results in the Mana Drain player taking infinite turns on the spot. Before, Mana Drain decks had to spend many slots in their decks on making sure that they had a way to win games. With Time Vault, they only need to spend a few slots on this, which allows them to be much stronger.
