Inquisitor Alpharious Ironskull
A former acolyte himself his inquisitor sent him and his squad down to an ork ravaged planet with the mission of recovering a holy relic recently tracked to the xeno swarming hell hole. His group was quickly overwhelmed by a mass of green skinned savages as they fought their way through their horded masses and their ramshackle villages from their landing site to the last know location of the relic they were sent to find.
The group reached their destination and recovered the holy relic before calling in for extraction from their low orbit ship. Unstable atmospheric conditions proved too harsh for an immediate extraction however, forcing the group to hunker down in the Dark Age ruins they recovered the relic from and make a stand until a drop ship recovery team could make a pick up.
They fought for hours, slowly losing members of the small strike team that were sent in for the extract, having already been significantly weakened by the various firefights they had with the orks on their way over to their current position. Before long it was only Ironskull and two others left who were providing sniper support. Ironskull having taken a glancing bullet to his head, shattering a large chunk of his head, and blowing out his eye. He remained conscious through this all, continuing his suppressing fire on the bottle neck of the door into the old factory, keeping the relic safe long enough for their extract team to reach them.
He received immediate emergency care on his head, most of his skull being replaced by a metallic replacement, and his eye replaced by a single red bionic. He refused all offers of synthskin to cover the metal skull he now possessed. Claiming instead the desire to wear his new skull for the world to see with pride. Better than any award, promotion, or medal it clearly signified his devotion to the Emperor.
The only survivors of the team being himself and his sniper support. His heroics, devotion, and faith earning him a promotion from simple Acolyte to Inquisitor himself, gifted a ship, and some crew. His sniper support were also rewarded with a slightly pushier position of which records are classified.