Sorcerer's Blood Stone

When Sorceror's Blood Stone enters the battlefield, if it wasn't cast, sacrifice it.
You may pay 2 life for each colored mana symbol in the mana cost of spells you cast. This effect works only for the amount of colored mana you pay. (For example, if you cast a spell with mana cost {2}{r}, you may pay 2 life and {2} to cast it instead.)

"The blood of the leaders is the seed of victory."