Captain Karnan is the Dominus Primus Draco, the captain of the Saurus Legion’s First Company. He is one of the most important Marines in the company, and his wisdom is highly valued.
Many, many years ago Karnan was a Scout attached to the Seventh company. In the process of fighting on the death world of Appendix III, Karnan was ambushed by Lictors. Five of them came in from all sides, and only the timely intervention of a falling tree saved him. Finishing off the squished corpses, he returned to the squad a hero. Everything after that happened rather quickly, and he ended up as a Terminator.
This of course lead to him accumulating yet more kills, especially as half the time he drew the long straw and got the assault cannon. He wound up as the Captain of the First Company, which just goes to show that you should never trust Scouts who claim to have killed the Lictors whose severed heads they bear.
In combat, Karnan wears a suit of artificer-worked Terminator armour, into which souls of dead Marines are bound. They have a nasty habit of absorbing excess psychic energy and throwing it around.
Karnan also carries specially modified versions of the standard Terminator sidearms. The Ruun Storm Bolter fires massively overpowered bolts at a furious rate. The Draco Power Glove is only slightly more powerful than a standard model, but has a small grenade launcher mounted on the back.
Karnan is escorted (in battle and occasionally around the beach and to parties) by four veteran Terminators who carry an assortment of weaponry.