Mjollnir

Mjollnir is an artifact; it is a reference to the hammer of Norse lore. It is a hammer for skill purposes. It does lightning damage, which few monsters are immune to. However, if a monster is immune to the shock damage, the hammer itself only does ~d12. For this reason, it is a good idea to two-weapon Mjollnir with another weapon which will do more base damage.

Mjollnir is the first artifact Valkyries receive upon sacrificing at an altar. If a Valkyrie is wearing gauntlets of power while wielding Mjollnir, she can throw it at enemies like a ranged weapon and it will usually return to her hand.