Alberich XIII was a warrior of Asgard that lived during the XVII or XVIII century. He is a protector of Odin, so, he is a rival of Athena. But, he is only a challenger, and not a traitor, like Megrez Alberich (his descendant).
Alberich XIII hunts various warriors, to fight against in a challenge, and always used his main skill: Nature Unity, that he created. He didn't have the same skills of Megrez Alberich (didn't uses Amethyst and a fire sword).
Before challenges Dohko, he wrote about the Odin's Sword and its relation with the 7 Sapphires. The work of Alberich's family, isprotected Odin and the sword.
Dohko with his power, discovered about the foible of the Nature Unity, and kills Alberich XIII, doing Megrez Alberich finds it shameful.