Malkaan Feirros is the current Master of the Forge for the Iron Hands chapter of Space Marines, and, as befitting a chapter of tech-obsessed lunatics, he also acts as a mix between a Chaplain and Techmarine. He also represents the first named Iron Hands character (Primarch excepted) to have been provided a model by Games Workshop since...fuck, FOREVER.
He's also a very long-lived marine, noted as having trained Kardan Stronos (who doesn't have a model despite having been in the fluff for considerably longer) and sharing his disdain for the autistic "replace all emotions" doctrine that plagued the chapter for millennia. However, he's still keen on upgrading and tradition, as he's responsible for carrying out the chapter's tradition of chopping off left hands before replacing them with cybernetic ones. In particular, he's quite content and capable of utilizing his emotions when the situation arises, such as when he manipulated the notorious shitheel Iron Father Kristos into managing the near-devastated Clan Raukaan by playing with anger.
Malkaan's already a pretty dangerous guy by dint of being a Primaris Space Marine in Gravis Armour with a 2+ save and a 2+ BS, but then come the weapons. Aside the two servo-arms provided by his harness, he also possesses the Gorgon's Fury, a Heavy Bolter (36" Heavy 3 S5 AP-3 D2) that's mounted onto the harness in place of the typical hand-flamer/plasma-cutter combo, an Signum array, and Harrowhand, his power axe (S+3 AP-2 D2) that's more than capable of chopping through anything in his way.
Of course, he's also tanky as all hell. On top of the 2+ save and 5 Toughness, he also ignores all wounds on a 5++ (owning artificer bionics rather than relying on the chapter's 6+++)and grants a 5+ Invuln to all friendly Iron Hands INFANTRY units within 6", giving him a means to beef up his guards. He also lets one unit within 3" use his BS of 2+, making for a great help when shelling things senseless or for getting the big guns to hit. Being a Techmarine, the Master of the Forge no less, he also has the means to fix vehicles, but his repairs always restore the max number of wounds, making him necessary for a heavy-vehicle/dread list.