Unbreakable Vow

When Unbreakable Vow enters the battlefield
choose two players.
•Whenever one of the chosen players draws their
first card each turn the other player may draw a
card.
•Whenever one of the chosen players gains life
for the first time each turn the other player may
gain that much life.
•Whenever one of the chosen players loses the
game the other player loses the game.