Gears

Gears is an explorator who has served the adeptus mechanicus for many years and may well be the oldest member of the crew, he has an arched back and wears the classic red robes of a tech priest, along with his trusty power axe and or walking stick he calls "the key" for some reason. Most of his body has been replaced by machines as is common for a tech priest, robotic legs, a mask that helps him breath a few robotic exterior limbs, and a few other bits and pieces are probably the only reason he is still alive. He is a quiet man but speaks when he thinks isn't necessary often talking through his rebreather which masks his true voice easy to anger yet a team player he is quite a piece of work and many wonder how he has even survived this long, his true age being unknown possibly even to himself. An adept fighter and technician, he rose to the ranks of the higher ups during his life time and is now head engineer aboard the ship, as part of the new specialist crew he arrived on deck when the ship was handed over to the new captian.
Followed by his trusty servo skull "Tungston" is always nearby and tends to scare new recruits when it observes them, two red eyes scanning everything around him. A small robotic hand is also attached to the servo skull for use when it needs to pick things up or move things. Fitted with a voice modulator one would sometimes hear it speak or make servo noises yet what makes it even creepier is that the skull never had a lower jaw. Sometimes found near Gears right shoulder it connects to the tech priest via a small wire and downloads information into the tech priest brain which is half machine, a small cable going into his hood to who knows where?
Physically the tech priest looks old and battleworn, yet he is still moving if somewhat slowly at times, small streams of steam making their way out of his maks every now and then, he walks with a metallic noise hitting the ground every few steps not the stealthiest of all the people on the ship, yet thes same metallic legs provide him with the speed he needs if he ever wants to get into close quarters. Should he take his robes off one would see two robotic legs and no mouth just a mask that helps him breath and keeps him alive, two external limbs one in the shape of a pincer type arm and they other a tendril like shape. A few robotic fingers on either side, lost while doing some machine work no doubt. 
He is looked down upon by some due to his agumentations and worshipping of the machine god but one gets used to such things as one of the adeptus mechanicus.