Derian Arkelius

Derian Arkelius is a member of the Orpheus Salient's Triumverate, as well as General of the Salient's ground forces.

History
General Derian Arkelius is the eldest son of the Noble House Arkelius on Scintilla. He is a tactician without peer, but his field leadership skills are weaker than would be expected of a man of his rank. General Arkelius is at all times accompanied by an elite bodyguard drawn from the veteran squads of the Scintillan 84th Grenadiers.

He feels that this sends a message to his men that they should always be expecting trouble and to never let their guards down. When General Curas was killed in action, General Arkelius immediately began lobbying Lord Militant Tetrarchus to be appointed to the post. While his request was never officially denied, neither has he been appointed Commander of the Orpheus Salient.

This is why, when Lord Commissar Theren proposed his deception, General Arkelius jumped at the chance. If nothing else, it would give him an opportunity to deny his sister the ability to make a stronger case for herself. His attitude towards the Deathwatch (and Space Marines in general) is barely constrained hostility. To him, Space Marines represent a force that should be under his direct control, and he sees them as nothing but glory seekers who are denying him the chance to prove himself worthy as Curas' successor.