What is the name of the substance Red Skull sought as powerful as the Infinity Stones in Marvel Comics?

Cosmic Cube

In 'Frozen,' who is Anna and Elsa's friendly snowman friend? Who placed Jesus’ body into his own tomb after the crucifixion? Who holds the record for the most career passing touchdowns in NFL history? Which defensive team had a famous nickname 'The Steel Curtain'? What popular RPG series by CD Projekt Red is based on fantasy novels by Andrzej Sapkowski?