"Older," he answers. "To be fair, Sif wouldn't have known about her, either. Loki and I didn't know she existed until my father told us right before his death. He used his powers to imprison her in Hel, but once he died she was able to escape her banishment. Shortly before I arrived here, Heimdall, Loki, Valkyrie, one of my Midgardian friends named Banner, and I all had to fight together to stop her."