Temple of Eternal Strife

As Temple of Eternal Strife enters the battlefield, you may sacrifice two creatures. If
you don't, Temple of Eternal Strife enters the battlefield tapped.
{t}: Add {w}, {b} or {g} to your manapool.
This Temple is less of a place of prayer than a monument, the living don't dare to come, the Lost
can't bear the pain of facing their fate.