Mirrored Depths
Plane -- Karsus
Whenever a player casts a spell, that player flips a coin. If the player loses the flip, counter that spell.
Whenever chaos ensues, target player reveals the top card of their library. If it's a nonland card, you may cast it without paying its mana cost.
Unexpected Results
{2}{G}{U}
Sorcery
Shuffle your library, then reveal the top card. If it's a nonland card, you may cast it without paying its mana cost. If it's a land card, you may put it onto the battlefield and return ~this~ to its owner's hand.