Thor

The thunder god of Norse mythology. When he infiltrated Thrymheim, he disguised himself as the goddess Freyja. While imprisoned in an ice prison, he was rescued by Klein, joined the party, and revealed his true identity after receiving Mjolnir from Kirito, defeating Thrym. Afterwards, he gave Klein the legendary weapon "Thunder Hammer Mjolnir," resized to be usable by humans, and departed.