A Part of the World Burning (GLOG Class: Barbarian)

    The latest engine of death to appear is appalling by its uncanny invincibleness. They hurdle trenches, crawl over shell craters and walk through forest unhalted by intense gunfire. With the death of the dashing romanticism of cavalry, the fighting seemed to take on a mere grim and sordid aspect. A dozen great machines crawling slowly (hardly faster than a man can walk) over the fields, always firing, firing at the soldiers seems somehow less compelling...
        - Weaving with Bright New Threads, a book of prophecy

    Practitioners of Manufacturing fall into two broad categories. The first type, the Manufactory, is a well-educated and respectable sorcerer who practices their Art like an engineer practices his science. The second type is more akin to a madman or a superweapon.

Source: Medieval Steampunk Knight 2 by obyekt

    What is an Armature, I hear you ask? It's a walking forklift, not unlike the Power Loader of Aliens or other exosuits of science fiction. Its function is more fantastical in the Unfinished World — an Armature is, briefly, a metal automaton like one of Vulcan's assistants, crudely bolted onto a human soul which provides it with animation. That's how the cosmology of the UW dictates that it work, but you could throw it into another setting as a product of the Serpentman Empire's attempts at interplanar travel, or as a divine blessing from a god of the forge to his most devoted cleric-hammerers, or as a wacky invention by funny haha smexy burlesque steampunk gnomes.

    I don't know if it's too powerful for your games. I hope that the Armature is (at least at 1st level) roughly equivalent to a barbarian, with an interesting dungeon-crawling twist of being very good at lifting the lids off of stone sarcophagi, setting off traps, and kicking down doors. You could lean into its random-encounter-provoking loud clankery if you wanted to add more consequences to its use.

Source: prototype Big Daddy, I think

Class: Armature

    You are an Armature, a man-machine, pilot and mechanism both, one soul in two bodies. Your changing form is fueled by the substance of Manufacturing. You have a pool of this substance equal to your maximum HP. When you would regain any amount of HP, you may choose to regain that much substance instead. 
    As an Armature, you may wear medium armor and use spears, guns and shields. You gain +1 to intelligence-related checks for every [template] you have in this class.

Skills: 1. Metallurgy, 2. Military History, 3. Court etiquette.
Starting Equipment: Concealed pistol (light, 10’ range), heavy leathers (as leather, weight like chain, half damage from fire), trigonometry text

• A Two Bodies
  
• B Customization
• C Assault Configuration
• D One Soul

Two Bodies
    You are a practitioner of the First Art and have a pool of substance like a Manufactory. Unlike a normal Manufactory you occupy the same 3-dimensional coordinates as a 10'-tall humanoid mecha made from glass and hot metal called an "Armature". You may pay 1 substance to swap places with your Armature at any time, so long as there is room for it to stand.
    Your Armature has as many hitpoints as you, 24 strength, 16 AC, takes half damage from conventional weapons and falls, and no damage from fire. Its limbs are medium weapons, and it can wield a heavy weapon in one hand for 1d8 base damage. The Armature is clumsy, can only move at a slow walking pace while upright, cannot move and attack on the same turn in combat, sinks in water, destroys ladders promptly, and requires 1 substance to take any action besides "pick up a heavy object" or "slowly walk forwards while holding a heavy object" (this includes attacking).
    Damage to your Armature can be repaired with two hours of swinging a wrench into empty air and cursing under your breath.

Customization
    For every [template], you may attach one upgrade or gizmo to your Armature. You will be able to obtain more of these in play; roll for a random one now. Expect the design and construction of a new upgrade or gizmo to take upwards of a week, the investment of a sizeable amount of gp, and perhaps the integration of unique treasures or mechanisms (such as a capacitor from a lightning-bolt trap, a wand of telekinesis, a vorpal sword, a unicorn's horn, &c). Swapping them out can be done at any well-equipped machine shop. Most require substance as fuel.

Assault Configuration
    After further modification and upgrading, your Armature can sprint faster than a horse and can crawl on all fours as fast as it can run. It can move and act on the same turn, and attacking with its hands or a weapon no long requires substance unless that weapon requires it for power.

One Soul
    When you would swap places with your Armature, you may choose to have it appear in a suitable location within 30' of you without yourself disappearing. It tracks its initiative separately but is otherwise under your control.

Upgrades and Gizmos:

1. Shoulder-Mounted Pepperbox. Host of barrels like a wasp hive. You may pay 1 substance to make an attack for 1d6 damage at 30', with -1 to-hit for each 10' past that.
2. Tower Shield. Occupies a hand. The Armature gets +2 AC, and anyone hiding behind it has complete cover in the form of an inch-thick wall of steel.
3. Pneumatic Grip Device. Comes with a built-in substance-powered winch. The grapnel can be fired up to 100'. Ascending/descending costs 1 substance per 10'/30'.
4. Incendiary Cutting Tool. Makes a cut in metal 6" long, 6" deep and 1" wide per substance. Deals 1d8 hellfire damage if used as a weapon.
   
5. Heart-Pumped Spotlight. Casts blazing sunlight in a 200' cone for 1 round per substance, dealing 1d6 damage per round to any undead caught in the light.
6. Deoptimized Venting Technology. May fling 20' per substance in any direction, with a pants-shittingly-loud explosion and a mushroom cloud of poisonous smoke.
7. Chainsaw Sword. A massive weapon with a sawtoothed edge. Pay 1 substance to rev up the edge, chopping through a tree-sized man or a man-sized tree. 
8. Spalling Recoilless Cannon. A weapon designed for killing Armatures and armored vehicles. Costs 4 substance to fire, has -1 to-hit for each 100' of range, hits touch AC for 2d10 damage plus the target’s AC. 
9. Foam Nozzle. A retractile hose ending in a funny-looking funnel. For 2 substance you may spray freezing, fire-extinguishing foam in a 40' line. For 3 substance, spray sticky and highly-inflammable goo instead. 
10. Extradimensional Chamber. A hatch on the Armature's stomach, just big enough for its hand to squeeze through, leads to 8 slots of inventory space.