Techmaturgy

Introduction

Techmaturgy is currently the least common of the three main branches of supernatural powers in the Grand Empire of Karadia. One that's actually notable for being almost entirely manmade (although it was believed to have been achieved under divine guidance). It was the Grand Empire that created the Network, a separate dimension of Reality that was then used as the local equivalent of the internet.
It was also populated by various network spirits, manmade equivalent of weaker daemons, who could be used as operators for various realworld machinery connected to the Network (or not - Network was later on metaphysically tied to the very concept of 'machine', meaning that the spirits could connect and operate various machines that were never designed with connection in mind, so for example remaining items and equipment from the pre-Network times. This also allowed the network spirits to interface with remaining ancient machines, such as those from the ruins of the Xylian Dominion or Kraad Technocracy, though how successful it was depended on the how advanced the machines was and how powerful was the spirit.
During the late Second Era it was the most common of powers - however close to 99,9% of the imperial techmaturgists perished during first twenty minutes of the Twilight War. Their permanent connection to the Network (together with some techmaturgic augments on their body) made them prime targets for the Hunter/Killer Spirits unleashed by the Hexmachina. Those that survived were typically weirdos who for some reason didn't connect themselves to the Network as closely and were overlooked by the hunter/killers during the initial assault.

Techmaturgy

Modern Practitioners

There is a very small number of active practitioners of techmaturgy. They are a necessity to the continuous existence of the Grand Empire, simply by the virtue of being the only people within its territories who can (to any degree whatsoever) operate the remaining Second Era hardware, for example the autofactories. While necessary and occupying key position for the survival of the Empire, they aren't many people willing to become techmaturgists.
This isn't due to the techmaturgy being har to learn, because it's not - in fact, anyone can be a techmaturgist. There is no mana core to be constructed, nor the years long training to assemble a network of mana nodes inside you. It's all the matter of having a right item or two, knowing how to use them and being ready to use them. In fact, techmaturgy can be used side-by-side with any form of Thaumaturgy, just like the Theurgy. Although unlike the latter, it doesn't steal enough of your time to prevent you from achieving greatness in thaumaturgy.
The real problem is that using techmaturgy in the modern Grand Empire tends to shorten your lifespan significantly. The Network is regularly malfunctioning due to lack of maintenance - even if you use the techmaturgy in a repeated way (for example access an autofactory's settings while standing in front of it) there is always a minuscule chance of the local Network segment malfunctioning and rerouting the connection through a data stack with a dormant hunter/killer spirit. And then you die. Painfully. And with a risk fo anyone in the vicinity dying too.
Sure, the chances of this happening are actually minuscule (it's like winning a lottery, but in reverse). However the chances of dying painfully after using techmaturgy skyrocket anywhere outside of well-tested locations. Who would like using a power that has something akin to a 5% chance of killing them (and anyone in the vicinity) with each usage? Sure, the risks are smaller with smaller acts (allowing techmaturgists to use various Second Era weapons for self-defense without having to worry about hunter/killers), and sometimes you can techmaturgists accompanied by combat machines (second era, or even xylian or kraad) that they hacked and managed to 'convince' to follow their vocal orders, without having to connect to the Network to order them around each time. However everything else is an eventual death sentence (because you WILL eventually roll critical failure and get murdered).
Unless someone manages to fix at least a part of the Network, the techmaturgy isn't going to return to being a viable prospect. Since the Grand Empire no longer knows how the Network was created - and the number of hunter/killer spirits dwelling in there seems endless - this is unlikely to occur anytime soon.

The Sub-Types

There are some surviving bits of information suggesting that during the Second Era some techmaturgists went as far as to replace their entire body with that of metal and crystal, turning themselves into what was pretty much a network spirit inhabiting a body. Those that went through that treatment were, however, wiped out by the Hexmachina during its initial decapitation strike. Today no one is even remotely close to the level of knowledge and augmentation to be able to try that. And even if someone did, it would be suicidal with all the hunter/killers dwelling in the Network.

The Tools

Techmaturgy is all about tools. From the magitek equivalent of a pistol through various side-equipment (including small drones carrying a variety of sensors, tools to efficiently and easily open various things, etc. etc.) into regular combat robots or even magitek tanks. However the problem is that safe for some Second Era (or Xylian/Kraad) models that were allowed to operate somewhat independently or simply do not require Network connection (so for example all you need is pull the trigger), using any such tools brings about a threat of hunter/killer spirit visit.
The larger and more complicated the item, the higher chance of that. The threat can be somewhat negated by excessive usage - for example Network surrounding more established fabricae of the Imperial Ministry of Production is at this point mostly secured, simply by all 'nearby' hunter/killer spirits being already eliminated at some point. However the cost in techmaturgist' lives for that was simply too large for cleaning the entire Network that way being a viable prospect.