Omnath, Locus of Mana | Magic: The Gathering
Formats Omnath, Locus of Mana is Legal in
Official Oracle Text for Omnath, Locus of Mana
Omnath, Locus of Mana gets +1/+1 for each green mana in your mana pool.
Official Rulings for Omnath, Locus of Mana
3/1/2010 : If a green mana you add to your mana pool has certain restrictions or riders associated with it (for example, if it was produced by Ancient Ziggurat), they'll apply to that mana no matter when you spend it.
3/1/2010 : Once Omnath leaves the battlefield, you have until the end of the current step or phase to spend whatever green mana is in your mana pool before it too empties as normal. There is no penalty associated with this other than the loss of the mana.