"Knights of Hell are hand-picked by Lucifer himself. They are of the first-fallen, first-born demons."

Castarice only appears when Castiel and Avarice are near death, they will become perfectly aligned and can only be told apart by his eyes when a black hue from Avarice will leak over the white and blue of Castiel's eyes. He will most often speak backwards but can force some words to be said forward with some strain. When Castarice appears Castiel and Avarice will soon die if not seen to immediately, He is a loyal and proud Knight of Hell and will not stop fighting until he is finished only then would anyone have a chance of saving him. If saved he will fall asleep for upward of three months as his body repairs itself, In these months he will remain Castarice and his body is still able to perish. In the final hours, When Castarice finally meets his end - Kirien, his familiar, being a ghost will take hold of them and lead them to the light, If not for him Castiel and Avarice would be lost to the void, on the other side Castarice will join Cain's army once more.

Castiel is a prince, but also a Knight because if you love your Kingdom and those in it you would put your life on the line for it.

{A Knight of Hell is a unique breed of demon directly created by Lucifer. As such, Knights are among the oldest and most powerful of their kind with only Lilith predating them. The order of Knights was built and led by Cain, the first Knight. Their exact rank in the hierarchy of Hell is not stated; however, they appear to be figures of awe among most demons, and refuse to obey demons they consider inferior to them.}

A bit of personal art I've been working on for a few nights between commissions, I'm rather happy with how this one turned out.
This explains a bit more about Castarice and Kirien and their ongoing story that owns my thoughts.

Art & Characters (c) echelonprince