They appear to be the most powerful fairies in the entire Fairy World. They were the first to banish the Darkness.
The Fairy Council decided that due to Poof being born from Cosmo, no more fairy babies should be born. However, Jorgen von Strangle wrote the supposed law on a sticky note, but forgot to officially enter it into Da Rules, therefor remaining legal.
While they put Timmy Turner on trial, they acted as his judges. They decided to age everyone up by fifty years and erase Poof from existance just because of Timmy's wish.
Distant Guardians Storyline
The Council will appear as rulers of the Fairy World, but they still serve Princess Celestia.
Former Freelancer Agent Michigan had a strong dislike for the Fairy Council, saying that they "only make the problems of the godchildren of the Fairies even worse", as well as publicly insulting them by calling them "ungratefull pricks".
Mich did attempt to fight them through physical combat, but before this could happen, Princess Celetia intervened. She and Zordon sent Mich into exile for his unnecessary aggression.