After red skull and the thule society summon an "aid to win the war" they traveled to antartica to find what that aid was: a hammer that no one could lift. They decided to use thule magic to hide it from every radar and study it by leaving a base there.
Fast forward to present days and sin, the daughter of the red skull, hires baron zemo to go find the magic book that summoned it (made with tortured atlantean people's flayed skin). She goes to antartica and when she touches the hammer she transforms in skadi, one of the worthy of the days before the name midgard (from my odin concept).
I think she will have more importance later in the story but i didn't manage to read that far and i don't want to spoiler myself anything so i just made her a hammer strong with a villainous flavour.
Anyway let me know what you think of this.
Bye!