All demons have a symbol that represents their names. The general shape is always the same, but they're not the same.
Setarra's Demon Friends
Balor (Fire) - Mayhem
Basically just that - a balor.
Crystal Demon (Earth) - Suffering
Has the ability to burrow underground and send crystal spikes through the earth, which - after piercing a human’s flesh, turns them into a crystal zombie.
The Radiance - Radiation Demon - blindingly bright, shining with an unholy glow - Corruption
Was captured by the church and placed inside of a stone sarcophagus which was located in the inner sanctum.