Creature - Elemental Avatar
Menace
When Scion of Calamities enters the battlefield, exile the top two cards of your library. Until the end of your next turn, you may play one of those cards.
Whenever a Mountain enters the battlefield under your control, you may aetherize Scion of Calamities. (To aetherize, create a token that's a copy of it, then exile that token.)
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