Tiamat

Tiamat is one of the Primordial Deities in Mesopotamian Mythology. She was known as the Goddess of Beginning, the primordial sea. Despite being a Goddess, she considers herself as a mother to all beings lower than her. During the 7th Singularity, when Tiamat was awakened, she was classified as a Beast of Humanity and nearly destroyed all of Uruk and its inhabitants but was eventually defeated. A few months after her defeat, you were able to summon her in the Alter Ego class. When she was summoned, she appeared in a childlike form, which was referred to as her Larval form but would eventually grow into her adult form that you recognize. Although Tiamat remembers you and her defeat during the 7th Singularity, she still holds a grudge from it but decides not to dwell on the past too much since her new duty is protecting you as if she was your real mother.