"I am the Son of Ragnarok, I cannot, no, I will not be defeated.!"
After Ragnaroks imprisonment on Level 12 of the Tartarus dimension, he used a large amount of his powers to manifest a clone of himself, which he named Fafnir. Fafnir was born outside the prison and lived in secrecy, being part of Ragnarok, he shared his mind and yet had a sense of individuality.
Being born of Ragnarok who was born of Miasma, Fafnir has immense power and is very intelligent. His abilities are largely unknown. But it is quite possible that he possesses the same powers as his creator. if only to a lower extent. He favors a physical body rather than his creator who lived as pure energy.
Fafnir attempted to release his father and all those hiding within the Tartarus, he was stopped by the ttitans of the Sozen Arc just before Astralagi stepped in. He alloed himself to be sealed away like his father to prevent him living the life of a tool.