msem-instigator

Enchantment - Aura

(Color indicator: Betrayer's Mantle is red)

Enchant creature
At the beginning of the upkeep of enchanted creature's controller, Betrayer's Mantle deals 3 damage to that player.

“. . . his loyalty, once betrayed, would forevermore be to himself alone.”
—Hemley Eggfeather

Card has other part: Dire Betrayal