Sumiko Sumimura, from the manga Kekkaishi, is so powerful that a shikigami clone with a seventh of her power was more powerful and skilled than just about everything except for the main character at his peak. Their powers being a form of space manipulation.
Katara and Toph Bei-Fong both became mothers between the two Avatar series.
Beatrix Kiddo gives us a sword that can cut God.
From the omnipotent side we also got various goddesses from various mythologies.