Karl Heisenberg was the owner and proprietor of a large industrial estate which was located in an Eastern European Village (possibly Romania). He operated an expansive Factory which descended deep into the earth; inside he alone conducted R&D which mainly involved combining man with machine, which mostly relied on body-worn Reactor technology he also created. Despite his seclusion to the rest of the Village, he remained confident and outspoken.
He also owned a large scrapyard as well as a few smaller standalone properties located near his Factory. Unlike the rest of the properties in and around Village, his industrial Factory stands out with its metallic structures and smoke stacks as opposed to the more classical and rustic looks for the rest of the Village.
House Heisenberg was one of the leaders of the Four Houses alongside House Dimitrescu and House Moreau to name a few; he and the other Houses worshipped
Mother Miranda who they all saw as a living deity of sorts — she infected
Karl and the others with a
Cadou which was an evolution of the Mold which was originally generated by
Eveline — the
Cadou gave its hosts unique abilities, some more impressive than others.
Karl, for example, was gifted with incredible strength, intelligence and he exhibited control over electro-magnetic fields (essentially he could manipulate metal, magnetic fields and electricity, much like Magneto from Marvel's X-Men series.) He also weilded a massive hammer of his own industrial design which was so heavy that no normal person could wield it.
His
Cadou infection from
Mother Miranda was not a gift as the Four Houses leaders were led to believe; they were actually selected for experimentation, and their 'evolution' was simply a side-effect of the
Cadou. Her goal was in fact to find the perfect vessel to revive her recently-passed daughter. Surprisingly
Karl as a vessel was extremely compatible and he was by far the most stable candidate, but he was ultimately rejected once a perfect host came along; Rose - Ethan and
Mia Winters'
Baby daughter.
It's also worth pointing out that
Karl was the most suspicious member of the Four Houses and held a particular disdain for
Mother Miranda, eventually learning of her true intentions which led him to first begin to build an army to go up against her and also attempt to bargain with
Ethan Winters with a view to team up and defeat Miranda together.
Karl appeared to have limited control over the Lycans, which was most likely because of the
Cadou that they all shared. On one occasion he has been observed directing them verbally, such as the time where he captured
Ethan Winters and allowed him to run through an assault course where he would be chased by Lycans and surprised by machinations of
Karl's design such as the classic descending spiked ceiling and a huge spiked drum which moved horizontally across a room and then rose into the air. He also appeared to have control over a PA system and CCTV system which had been wired up.
His Factory was his main base of operations; it appears that he resided there for most of his time in the Village. Inside, he mainly worked on his mass-produced Soldat units which were experimental
Cadou hosts which had been augmented with mechanical apparatus and a Reactor. The Soldat was essentially a regular infected human but with surgically implanted devices such as visors, powerful drills and body armour. The Reactors were strapped to the chest, but the Reactor Cores had to be exposed due to the heat that they produced - they glowed Red with energy and served as a weak point. The intelligence of the Soldat was such that they recognised this and occasionally crossed their arms to cover up the Reactor. Interestingly the blood of the Soldat was more of a dirty yellow colour; it's not known if they had a replacement blood or this was an effect of their initial
Cadou infection. Initially, these units were created by
Karl, by hand - and eventually he began to mass-produce them where they would be created on a production line and then travelled through the entire Factory floor on a hanging rail system. Then, they would be kept in storage in a dormant state until such time they were needed. Occasionally they would activate automatically but in most cases they would remain disabled until summoned by
Karl.
Another unit created by
Karl was the
Sturm. This was a unique experiment that was the combination of a
Cadou infected human and an aircraft turboprop engine. Suffice to say, he was disappointed with the results, despite its apparent invincibility. He eventually left of to its own devices on one of the lower Factory floors until such time he could figure out a way to use it, which he eventually did when
Ethan Winters arrived in his domain.
Eventually things came to a head with Ethan when they met in his Factory shortly after communicating remotely via television sets. They disagreed over the future of the Village and decided to go their separate ways - leaving
Karl to drop Ethan underground to where the
Sturm was located, with the view of eliminating him. At the same time,
Chris Redfield had infiltrated the Factory and was using resources and intelligence he found there to build a contraption which would both be able to combat
Karl directly and not be susceptible to his powers over metal. He also lined the Factory with explosives in secret while
Karl was engaged with Ethan.
As Ethan made his way through the Factory and destroyed countless monsters and machinations including the
Sturm, he eventually found his way to
Karl who by this point had had enough of Ethan.
Karl then forcibly began augmenting his own body with hardware which caused him to mutate into a large monster with immense power. Fortunately the device which Chris had devised was able to fight back against the machine. At one point
Karl was able to launch Ethan into the air and separate him from the device, rendering him defenceless.
It was at this point that Chris detonated the bombs which he had placed around the Factory which immediately caught the attention of
Karl - all of his hard work and creations were destroyed and his goal of defeating
Mother Miranda was no longer feasible. He now had only one aim left; defeat Ethan. So he now used all of his remaining power to attempt to overwhelm him.
Karl uses a huge amount of energy to create a vortex above his head which would destroy anything that entered it. By some stroke of luck however, Ethan was able to grab onto Chris' machine while he was hurtling through the air and fire a missile directly into the centre of the vortex which proved to be fatal against
Karl.
Dying,
Karl begins to crystallise and leaves behind a husk. Even in his throes of death, he vows to kill
Mother Miranda. But he quickly succumbs to his injuries and his machine body lay to waste.