Borremose Fen

Borremose Fen enters the battlefield tapped, and does not untap during your untap step.
Whenever two or more non-token creatures an opponent controls dies, you may uptap Borremose Fen.
{b}{b}{b},{t}: Put the top three cards of your library into your graveyard. Each opponent loses X life and you gain X life, where X is the total converted mana cost of the cards put into your graveyard this way.
{t}: (Add {b} to your mana pool.)