Soul Tarn

Soul Tarn enters the battlefield tapped, and
doesn't untap on your untap step.
Whenever two or more creatures die simultaneously, place a Soul counter on Soul
Tarn and untap it.
{t}: Add X mana of any combination of colours
among creatures in all graveyards where X is the
number of Soul counters on this card.
"Son, this is a sacred place. One day you will travel through here and pass onto the next world..."