Shirou in Another World.

Volume 0: Prologue

Breathe in. Breathe out.

Another spike of pain racked Shirou's frame as he rested against the tree. His body was in shambles, nearly spasming in pain from the stress he was forcing his prana circuits through. Shirou bit back a gasp of pain as another tremor shocked his nearly crippled prana circuits. Of the 27 original prana circuits he had, only 5 were left barely running. His stock of 570 structurally altered nerves-turned-prana-circuits was reduced to a meagre 50.

Shirou grimaced to himself. It had taken him 10 years of blood, sweat, and tears to alter and reinforce his nerves into fake prana circuits that did not break. The only reason all 570 prana circuits survived was due to his negotiations with the Einzbern family head Jubstacheit. In exchange for his services and noble phantasms, Shirou had requested to work together with the Einzbern family for research.

The agreement worked beyond what was expected. The Einzbern family's alchemy and structural manipulation had improved by leaps and bounds with the access to several noble phantasms Shirou carried. His structural analysis proved to be equally vital as it allowed the Einzberns to perfect many of their projects.

In return, Shirou was granted more access and even assistance from the Einzberns. Together, they were able to develop his structural analysis beyond theory. Shirou's lessons in the foundation of magecraft and structural analysis allowed him to develop a style to analyse and break down most types of magecraft he was familiar with.

But one of their greatest achievements was the fake prana circuits Shirou had. The Einzberns and Shirou had found a way to artificially manufacture prana circuits. Shirou's former prana output of 30 units had been boosted to 600 in the past 10 years.

This breakthrough was the only factor that allowed Shirou to survive this long against the magnitude and calibre of his current opponent.

Primate Murder. The first seat of the Dead Apostle Ancestors.

It started a few hours earlier, when one of the Einzbern family research facilities had declared an emergency and requested immediate backup from nearby facilities. Shirou was in the Einzbern manor with Jubstacheit discussing modernising the Einzbern computers which his father, Kiritsugu Emiya, had introduced decades ago. Naturally, he was the first to respond. Jubstacheit had long since learned of Shirou's tendency to help people despite the situation. In fact, the treatment of Einzbern homunculus changed for the better after Shirou learned of them. He quickly became their favourite visitor.

When Shirou arrived at the facility, it had been utterly demolished. As if a natural disaster had hit the area, including the surrounding forest. Splotches of blood and few mangled remains were all that was left of the Einzberns. Whispering a few short parting messages for the dead, Shirou then started tracing the panicked tracks that led into the forests in hopes of finding the cause of the events.

That was when Shirou found himself ambushed by the Monster of Gaia.

The next few hours were a whirlwind of clashes between noble phantasms and an unstoppable force of nature. The forest was flattened and the surrounding area cratered from the powerful exchange between a living human armoury and a monstrous beast of nature.

Shirou glanced at both sides behind him, reinforcing his ears to hear even a sliver of sound from the movement of Gaia's perfect predator. He knew he couldn't escape Primate Murder's perfect senses. He could not run, nor could he fight at the current state he was reduced to.

What little hope he had of survival was gone after their first exchange. The White Beast of the Dead Apostle Ancestors would kill him before the Einzberns reached him. Even the combined Einzbern and Emiya resources wouldn't be enough to stop such a beast.