Helm of Obedience [Alliances] Mythic Edition When they do

When they do

Set: Mythic Edition Type: Legendary Planeswalker — Karn Rarity: Mythic Cost: {4} +1: Reveal the top two cards of your library

(At the beginning of the upkeep of each of those creature's controllers

Set: San Diego Comic-Con 2018 Type: Legendary Planeswalker — Nissa Rarity: Mythic Cost: {3}{G}{G} +1: Untap target land you control

Whenever a creature you control dies

Helm of Obedience [Alliances] Mythic Edition When they doSet: Alliances Type: Artifact Rarity: Rare Cost: {4} {X}, {T}: Target opponent mills a card, then repeats this process until a creature card or X cards have been put into their graveyard this way, whichever comes first. If one or more creature cards were put into that graveyard this way, sacrifice Helm of Obedience and put one of them onto the battlefield under your control. X can't be 0.