Cethlann

Cethlann is the wife of Balor and the matriarch of the Fomori, she was once a fertility-goddess and prophet who Dagda respected yet she always held him in contempt and would happily indulge in the worship of the Watchers after Balor became corrupted.

Viewing her horrific transformation as a blessing Cethlann was amongst the most eager of the Fomori to engage in open war with the other gods and was a fearsome enemy who managed to strike Dagda with a surprisingly powerful blow moments before he cast her into the depths of the ocean alongside the rest of her kind, this blow shattered a piece of Dagda's armor off and would be the start of a legendary blade known as Dagda's Shard - which would ultimately become the property of the Avalon race known as the Valkyrie, who kept it hidden until many centuries later when the Fomori sought it for themselves and had to be kept at bay by Thor and a collection of other Avalon heroes.