Welcome to Demongate Academy is based very much on Paragon Universal RPG's Demongate High setting. As such, each character has their own power type that they will use throughout the story, and any official sidestories they appear in.

First off, Mane 6
Twilight Sparkle: ESPer - User of psychic powers, can consciously exert minor control over the laws of physics (elemental control, telekinesis, past/future sight, scrying, mind reading, gravity control, teleportation, time manipulation)
Applejack: Spirit Energist - Manipulator of internal spirit energy, can form energy into a weapon or turn it into lethal elemental blasts
Rainbow Dash: Cambion - One who is descended from a demonic entity, and has thus gained both unnatural appearance and powers.
Rarity: Artificer - Crafter of supernaturally powered items, from paper wards to chalk circles to fully functional talismans (Magic Items)
Fluttershy: Shaman - Caller of nature spirits, can bestow special blessings through ritual chants, and can summon forth a projection of her own soul to fight on her behalf.
Pinkie Pie: Petitioner - Chosen by the Heavens to call upon angelic servants to aid her in times of need. Also has a Guardian Angel watching over her.

Canon Background Character Groups (With Planned Sidestories)

Vinyl Scratch (Cambion), Octavia (Songstrel/Inheritor), Garble (Dragon/Spirit Energrist), Vesker (Changeling/Spirit Hunter)

Roseluck (Touched), Carrot Top (Mystic), Lyra (Demon Artist), Bon-Bon (Alchemist)