Commander Dorian was the commanding officer of Brute Squad. He was attributed to many of their victories under the Terran Dominion, and was later transferred to the Moebius Corps. He believed in taking risks during battle, and that doing things "by the book" was for rookies.
Biography
Commander Dorian served the Dominion, leading his Brute Squad to victory on Korhal, Ghobi Station, and Pantera Prime, and pulling his squad through on Braxis. He personally fought regularly against the pirate Zeus and his group the Players' Club. Through a series of backroom deals, he and his men were transferred to the Moebius Foundation, and put under the command of Major Braxton. In both the DMC and Moebius Corps, he had a habit of getting on the wrong side of his superiors.
Under Moebius
Dorian was tasked to retrieve a xel'naga relic from Beta Saul, and was ambushed once again by Zeus and his group. Dorian defied convention when they used their Moebius dropship as cover, and flanked the Players' Club's forces, damaging the dropship in the process. When Zeus was ready to escape, Dorian defied direct orders not to peruse him, but Zeus still managed to escape.
Dorian was transferred to Revanscar, and he was transferred from Braxton to Lieutenant Colonel Sparks, who assigned him as security detail for the facility's Sector Six. Dorian disliked Sparks and envisioned his gruesome death, but followed orders. The job was slow for the first two days, until Professor Benz came into the sector's restricted area with a plasma gun and started shooting indiscriminately. He was subdued, but at the cost of two lives.
Dorian was reprimanded for the deaths, but given no details nor access to the restricted areas. When his men complained about mysterious dreams and Spanneti wandered into the secure sector with little recollection as to why, he checked them into the medical wing, who prescribed them flu medication. Dorian decided it was time to personally investigate, and defied orders to check on Benz. Benz had self inflicted injuries, drawling on the walls of his cell, and kept repeating the words "I obey." Dorian then went to check on Lieutenant Zimmerman, who had vanished, only to find she had killed herself.
Dorian then heard a psychic voice, stating he was among "the Chosen." He shouted back defiantly they he would not obey it, and he would kill whatever was causing the disturbances. He gathered his squad together, who debated leaving he facility, but Dorian insisted that they had to kill the creature. He moved into Sector Six's restricted area, and subdued Lieutenant Colonel Sparks with nonlethal rounds. However, behind him he heard gunshots, and he turned to find all lab techs and Cranston dead. The rest of his squad insisted he had gone insane, and they moved on further into the sector.
As they moved, a realization dawned on Dorian; in order to kill Cranston his squad would have had to use lethal rounds, which were inside their suit. Because of that, they would have had to have lethal rounds from the beginning, which would have meant they killed the lab technicians and not Cranston. He went to confront them, but the xeno entered the room and assaulted Dorian's mind. Dorian resisted, but in the end was broken by the hybrid, uttering the words "I obey."
References
Neilson, Micky. "Sector Six." (Oct 27, 2015). Blizzard Entertainment. StarCraft Lore: Sector Six Accessed 2015-10-27.