Oha (The Meditation Ghost) is one of the seven ghosts of the universe and first in command to Irsa.
Irsa Grimm is the spirit of an elder witch. She is in conflict with her once husband, the warlock Vargas Grimm. She remains hidden deep within the void to escape detection.
Viper is second in command to Irsa and in charge of field operations. Even though Oha is first in command Viper is always the one getting his hands dirty. He is a ghost without the sacred ranking of the universal seven. His enchanted mech suits make him a powerful force.
Kirby is one of the last known gargantuas. He can call upon the spirits of his ancestors to grow to towering sizes. After using this power Kirby reverts back to his ghost form and slowly grows back to his regular state as his strength returns. He must be careful though as remaining a giant for too long can kill him.
Eos is a mythical ancient beast sometimes known as a ghost catcher. In prehistoric times his race would hunt ghosts until The Great Mutations occurred. Those mutations lead to plagues, famine and eventually wars.
The Brute Squad is a group of human mercenaries devoted to serving magic traced back to Eos and ancient times. Their helmets are a tribute to the original ghost Brutus The First.
Serkan is a servant of evil. He is the creation Lord Vargas made from a ghost known as the Blood Glops and a dwarf. His powers stem from Vargas himself which makes him extremely dangerous.