OVA
Description
Yggdrasill leads the angelic organization Cruxis as one of the Four Seraphim, beings existing for over 4,000 years. His true identity is Mithos Yggdrasill, a half-elf originally from the village of Heimdall. He manifests as a blond-haired, green-eyed male with the physical stature of a 14-year-old boy, standing 153 cm tall and weighing 41 kg, despite his millennia-old age.

Exiled from Heimdall due to discrimination against his half-elf heritage alongside his sister Martel, Mithos later became a legendary hero during the Kharlan War with companions Yuan Ka-Fai and Kratos Aurion. He forged pacts with Summon Spirits and wielded the Eternal Sword to split the world into Sylvarant and Tethe'alla, halting mana depletion from magitechnology but violating his pact with the Summon Spirit Origin. The central catalyst for his transformation into Yggdrasill was Martel's death at the hands of a human traitor. Her soul was preserved within her Cruxis Crystal and later fused into the Great Seed using the Eternal Sword.

Consumed by grief and a distorted interpretation of Martel's wish for racial equality, Mithos adopted the persona of Yggdrasill. He founded the Church of Martel, declaring her a goddess. His ultimate goal became the "Age of Lifeless Beings," seeking to transform all races into uniform, immortal angels via Cruxis Crystals to eliminate discrimination by erasing individuality. To revive Martel, he manipulated bloodlines across both worlds for millennia to produce a vessel matching her mana signature, resulting in Colette Brunel's birth. As Cruxis leader, he orchestrated the Journey of Regeneration, using the Chosen's pilgrimage to awaken Martel, while establishing human ranches and oppressing half-elves through the Desian forces.

Yggdrasill maintained control by presenting himself as distinct from the hero Mithos, masking his true identity. He briefly joined Lloyd Irving's group in his child form, befriending Genis Sage and revealing internal conflict. His plans culminated in transferring Martel's consciousness into Colette's body. Martel rejected his methods and returned to the Great Seed, shattering his sanity. In a final confrontation at Derris-Kharlan, Yggdrasill attempted to destroy the existing worlds to create a new one solely for himself and Martel. Defeated by Lloyd's group, he expressed no regret before his permanent death.

In the spin-off *Tales of the Rays*, an alternate Mithos exoflects Martel from a time prior to her death. This Martel learns of her future and is later abducted for a possession ceremony before being rescued. Another incident involves an attempt to exoflect the Spirit Martel, inadvertently summoning the souls of sacrificed Chosen; these souls temporarily influence Martel until Yuan's intervention frees her.

The name Yggdrasill derives from Yggdrasil, the world tree in Norse mythology. A statue based on his concept art appears in *Tales of Berseria* as a collectible item.