Countess Aoife Silverfang

When Countess Aoife Silverfang enters the battlefield,
Sacrifice X monsters you control and place that
many black, white, or, red land card from your
deck onto the battlefield, your opponent (s) loses
life equal to the number of monsters sacrificed
this way, and you gain that many life.
{t}You may tap, Countess Aoife Silverfang, add
one Black, White, and Red mana to your Mana
pool.