Madness incorporated Zelhart, the blood above his armor shinned a vivid red. This was the nest of evil in the Kingdom, a place with as much evil as in Zelhart's heart, this place together with the memories from Luther's death made him lost control once again.
Losing control of everything, Zelhart fought and killed. There was no way to distinguish who was from the resistance or part of the Blood Temple, but he didn't care, the point of his blade made no distinction between them because there was apparently no good at all.
The fruit of the memories from when he killed Luther, all the anger and despair that devastated his heart and mind. He remembered fighting against the flow and how painful it was, in the end, the result was the same so there was no point to hold his anger.
'This place is infested with evil, I must purge them.' Zelhart repeated on his mind over and over again.