When Obsidian Key enters the battlefield, return a land you control to its owner's hand.
: Add or to your mana pool. Obsidian Key deals 1 damage to you.
, Sacrifice Obsidian Key: Add to your mana pool.
: Add 
or 
to your mana pool. Obsidian Key deals 1 damage to you., Sacrifice Obsidian Key: Add 
to your mana pool.
