Oh, this is terrible news indeed. Prometheus shakes his head gravely, although there's nothing about the situation that he blames on a lack of forethought. It is a sad misfortune, made worse by how closely Thor and his allies missed retrieving the stones from Thanos' grasp. How oddly fitting for such a monster to use the stones on one another, to destroy that which gave him such power to begin with.

"I am sorry," he says quietly. He puts his hand on Thor's shoulder, turning towards him, body language open and accepting. "I am so sorry. I know you were hoping..." He trails off. He was hoping, too. He doesn't want this to be the ending of Thor's struggles. "Listen, friend. Killing Thanos may not have changed the past, but a madman like that, who knows what else he might have done. You were right to eliminate him. It was a justice done."