Powers: Once given form, Valkyrie was a skilled sword fighter and proficient hand-to-hand combatant. She also possessed super-human strength and had total control over Thor.
Bio: First appearing only to Thor, it was later revealed the Valkyrie was the embodiment of Thor's then-current madness. She normally spoke to and was visible to him, though Adam Warlock could see and hear her due to his Soul Gem. She later gained physical form, but was effectively destroyed when Thor regained his sanity and banishes her.
Notes: Though she first appeared in Thor #460, her true nature wasn't revealed until #468.