It can be found in the Extradimensional Crisis pack from the ExtradimensionalCrisis set
The other side of the card hasnt been cast yet, and therefore isnt active
But because you know that they know, that creates the opportunity to bluff having specific instant-speed cards by choosing what mana to leave unspent on your turn
One-card searches that turn singleton variance into deterministic toolboxes Demonic Tutor, Vampiric Tutor, Mystical Tutor, and the rest
3 Hidetsugu, Devouring Chaos (Neon Green) - $195.99 One of four variants of this classic demon, this particular version of Hidetsugu, Devouring Chaos is the Neon Green variant
cards, despite many of these new cards being stellar upgrades to existing archetypes