Thauma-tech holds a pernicious dichotomy within – while it manipulates earth-shattering energies on a regular basis, it does so without the direct control of an archmage to harness them; whereas said wizened wizard would be able to dissipate the powers in the case of a mishap, thaumatic technology often goes up in spectacular fireworks.
So it was with the factories of Sir Waldemar Walthers, where wondrous brews were produced to end many of mankind's ills; also numerous were his weapon works, where rather permanent solutions for humanity's difficulties saw the light of day in rather disturbing quantities.
The colossal machinery, brimming with powers not understood by the common worker and barely so by many of the engineers, besides churning out merchandize of various degrees of lethality, also had the unpleasant propensity to ripple the fabric of space-time and release mutagenic gasses, confusing geases and gears flying at rapid velocity. Worst of all were the spirits and demons though. Red lights flashing, alarm horns blaring and fires springing up everywhere were always a sure indicator to get one’s ass out of the factory, lest it be carried away in the belly of some hellspawn.
After witnessing such an accident first-hand, Sir Walthers had an idea - as he was wont to do, for ideas sprung up in his mind after the strangest inspirations. You have to understand, this timid looking gentleman with a neatly trimmed moustache and hat that never matched his suit or pants was often struck with ingenious, unpleasant and disturbing ways to kill people, with no malice nor intent on his part though, after watching, let's say, leaves on the autumn wind or a highly caloric cream pie ("You see, the foam will hold the foemen fast, while the sprinkles, I mean carnivorous maggots, hatch under the influence of the generated heat and chemicals, and eat the enemy alive, and when overfed, they will explode, blowing the whole thing to smithereens.") After witnessing a catastrophic accident during which unfortunately fire elementals, demons and spirits from beyond rampaged through one of his factories in a badly orchestrated symphony of destruction, another of those ideas that cause the innocent to make holy gestures of warding struck him.
Those destructive entities seemed to mingle, steal power from each other, and take on the attributes of the others. If only one could… but yes, why not?
Half a year later, Indomitable Industries released two new products, the Ecto-Burner Mark I and II. Capitalizing on the general hunger for power and destructive intent of the less savory of spiritual entities, the two-man weapon holds processed essence from malevolent ectoplasm in one container, stripped from wraiths, shadows, specters, haunts and their ilk in the case of the Mark II; the Mark I utilizes the energy of demons, to greater effect at the cost of safety. The container holds the essence in a pentagram field, with a switch being able to break the seal temporarily. The rear man of the team is responsible for the second tank as well – that one holds pure condensed fiery death – distilled fire elementals, charged hellfire or dragonflame. A carefully dosed amount of ectoplasm, little more than a ball of fury and hatred, is dosed with this volatile treat, then released by the gunner towards the enemy, a specter wreathed in a burning halo. Briefly will it rage, searing anyone it can reach with its conflagrant aura. Should demon essence be used, the released entity will rage far longer and with great ferocity - yet this has its own drawbacks.
The fiery specter can be hurled by a fully charged apparatus up to a hundred yards; as the batteries carried by the gunner lose power, maximum firing distance will decrease. An uncharged launcher does little more than release a raving mad spirit right in front of the team. Using essence harvested from incorporeal undead the apparition will remain active some ten to twenty seconds; a demon-powered shot will enthusiastically torch anything it can get close to for a few minutes.
Smiling, Sir Walthers notes that indeed, energy harvested and processed by his works is the sole even remotely safe way of using his wondrous engine of destruction - simply using a captive spirit (for indeed, the container can be used as an impromptu ghost-trapping device) as ammunition will result in releasing a burning spirit that remembers its confinement and will come back to get you and your family. ("We ran a dozen trials with complete spirits. I had to hire twenty new employees” Sir Walthers says, “it was an interesting sight though.")
"I have a vision", Sir Waldemar whispered to his aide in a conspiring tone. The youth tensed up, for he knew well what sorts of nightmarish fairytales usually follow. "I imagine a blanket!" He exhaled in relief. How harmful could a blanket be? "A soft, ephemeral blanket, spreading…" "Yes, Sir, a blanket indeed. Perchance you are ready to sleep?" he added in good hope. "No, it’s the foemen who will sleep eternally – or not, if we reanimate them – under a blanket of ectoplasm, which will be burning. And poisonous. With hypnotic lights…"
Two men are needed to haul the heavy (60 lbs) apparatus; usually they will wear medium armor. The rear man carries the spirit and fire tanks and controls the flow of the essences to the gunner (he can determine whether a shot will be large or small, and whether it should have more staying power or more fire). The gunner aims the device, and carries the thaumic batteries needed to propel the burning spirit towards its target.
The batteries can be recharged by a wizard or in about any thaumatech factory; the spirits have to be processed in a screaming contraption lovingly dubbed 'the Soul Mill'.
Most importantly, the 'shots' are guided by the spirit's malice and hunger, actively seeking victims. You could fire one into a building and be certain it ferrets out anyone hidden there, unless he's somehow concealed from a spirit's senses. It also means that if you happen to be closest to where your fiery wraith landed, it might return to you.
It's possible to combat the projectiles much like one would incorporeal undead, with the added risk that if it is slain before it is extinguished, the flames will be released in a spectacular explosion.
As for the cost, Indomitable Industries can produce the Ecto-Burner quite cheaply, but the fuel and necessary recharging of both tanks and batteries incur significant running costs; yet it's imperative not to skip maintenance, for an uncharged tank can release its contents without any warning.
*Obviously, espionage and counter-espionage concerning this destructive toy will offer lots of opportunities for sneaky PCs.
*The Holier-Than-Thou Empire has declared any use or sale of the Ecto-Burner anathema and prohibited even shipping it through their lands. The lords of Tyranaria and Mordenheim would love to lay their hands on a few pieces though; the illegal goods have to traverse the lands of said empire though. And, if you manage to deliver the shipment, you have to live with the consequences of it.
*Enterprising and adventurous PCs can of course make a buck by delivering captive demons and spirits to Indomitable Industries - makes for the added fun of having to catch the things into a container. Likewise, their allies and henchmen may try to rescue their demonic master before he becomes ammo.
*The forces from below do look down upon such blatant disrespect of their majesty. A cultist may earn favor by bringing innovative and cruel justice upon Waldemar Walthers.
*Concerning Waldemar, what if some malevolent entity of destruction is using him as a conduit to wreak havoc?
*After two years of neglect, the Ecto-Burner supplies at fort Backwater are in a desolate shape. It falls to the PCs to bring them to the nearest Indomitable Industries works to bring them back in shape – which is two weeks through rugged terrain, foe-infested none-the-less.