Dreyfus actually starts off as a villain. One of the two holy knights plotting for control of Liones.
But both him and Hendrickson were corrupted by an evil demon ten years prior.
With the Demon Fraudrin taking his body as his vessel for a long time.
I never understood why. Fraudrin was definitely far more dangerous in his true form especially with his full size power.
After he’s freed he’s definitely on the side of good. And a wonderful father.
His importance fades as the holy war escalated. Got a little boring.
He even managed to inherit full size from Fraudrin and we never see him use it again. Waste of potential.