Notes:

Source
From 'Magnhild Replica' to 'Magnhild Replica "Signe"': (Fire Element)
A Hammer based and replicated on Nora Valkyrie's Hammer. The fire element within the weapon compensates the lack of it's grenade-launching function. See the explosion of fire in every swing.

From 'Gunnhildr' to 'Brunhildr':
A Hammer based on Nora Valkyrie's Magnhildr. It's lost its explosive power in exchange of pure unadulterated power and rocket-packed swing. Swing your way to the annihilation of the Grimms.

From 'Thorhildr' to 'Mjolnir': (Lightning Element)
A Hammer with incredible power. Each swing brings tremors and lightning storms to the battlefield. Become one with Thor, the god of thunder!