When Watery Marsh enters the battlefield, return a land you control to its owner's hand.
: Add to your mana pool. Return Watery Marsh to its owner's hand.
, Sacrifice Watery Marsh: Add to your mana pool.
: Add 
to your mana pool. Return Watery Marsh to its owner's hand., Sacrifice Watery Marsh: Add 
to your mana pool.
