Nemesis

Goddess of Retribution.
Daughter of Erebus and Nyx. Estranged member of The House of Erebus.
First appeared in Season 1:
Fionn met her while battling The Oneroi at the end of Season 1, she tried to take Bodhi to Tartarus in the second part of The Oneroi episode.
Restrained her aspect when Fionn and his squad took an alternate route on their way to meet Morpheus during The Tartarus War, his mission to rescue his father, Lucifer.
Fionn met Nemesis while the rest of the party were sleeping or on guard.
He had a long discussion with her ranging from philosophy to theology, and Fionn later marvelled that among the gods these two subjects are the same.
She warned that travelling through her realm in Tartarus was perilous, poisoned thorns that could puncture any armour may spring from the ground, the very land becoming murderous. Her aspect is retribution and any who travel through her realm will find their flaws heightened, particularly hubris.
She did not mention and Fionn did not remember having met her while battling The Oneroi at the end of Season 1, she tried to take Bodhi to Tartarus in the second part of The Oneroi episode.
While talking about Aspects, Nemesis mentioned both justice and retribution. Fionn asked her if she could allow him and his friends to pass, she said she may not be able to stop her aspect from manifesting if the party's flaws showed. Fionn put forward the idea that it isn't justice if it isn't tempered and that if she can't control her aspect, it isn't truly her own. He found the debate enjoyable and interesting and told her so, she agreed to try to restrain her aspect and thanked him for the discourse.