Ghalama, Magma Vizier

At the beginning of your upkeep, each opponent reveals a card from their hand at random.
Whenever an opponent reveals a nonland card, if they have already revealed a different card with the same name this game, Ghalama, Magma Vizier deals 3 damage to that player and each creature and each planeswalker that player controls. If a creature or planeswalker dealt damage this way would die this turn, exil