Kiritsugu Emiya's intentions were very clear.
He — was here to kill.
To ensure that his wife and daughter would no longer be harmed.
Ever since he had let go of the unrealistic and lofty ideal of being a hero of justice and accepted the harsh reality, the only thing that motivated Kiritsugu was his family.
For the sake of his family, he was willing to do anything, even employing more ruthless methods than when he had pursued his ideal of justice.
After settling into the Matou family's mountain villa and enjoying a long-overdue, overly lavish breakfast with his family — considering the presence of a certain person with a voracious appetite, Shinji had arranged for a truckload of ingredients to be delivered overnight — Kiritsugu did not linger in the comfort of home. He promptly drove back to the city.
Although Shinji had promised to handle everything, urging Kiritsugu to stay home and spend time with his family, calm their emotions, and make sure the two vampires didn't run off, Kiritsugu simply couldn't sit idle at home.
It wasn't that he didn't trust Shinji; he just couldn't stand doing anything while his family was under a mortal threat.
It was also, in part, an excuse to find some peace. His wife, Irisviel, and his daughter, Illya, were both naturally lively individuals, and now there was also the equally restless Natalia and Shirley. While things were going well and there hadn't been any dramatic conflicts, Kiritsugu still felt somewhat out of place and wanted to find a quiet spot to clear his head.
Irisviel, Illya, and Shirley objected to him going out — after all that had happened the day before, they thought he should stay home.
But Natalia supported him, saying, "Now that's the Kiritsugu I know — efficient and quick to act. If it weren't for the fact that it's daylight and I'd promised Shinji not to leave the villa, I'd be going with him to get things done."
It seemed that, in the end, a mother's perspective on her son was different from that of other women.
Thanks to Natalia's persuasion — "Just let him go. Even if he's physically here, his heart won't be. He needs to go stir things up." — Kiritsugu set off.
True to his famed title of Magus Killer, Kiritsugu, a hunter with more than two decades of renown, might have been outclassed by the newer generation in terms of sheer ability, but his mindset and experience were still beyond what the younger generation could match.
While Shinji had his sister investigating land and property transactions and Medea analyzing the Command Seals, Kiritsugu did only one thing — he went home and started surveillance.
After all, he had lived with the Einzberns for nearly ten years and was deeply familiar with their ways, especially Achtd's methods. He knew that Acht would never let traitors go and that he would surely send someone to investigate. All Kiritsugu needed to do was wait, and he would eventually find a clue.
He didn't even inform his often-clingy (one-sidedly) sister, Taiga Fujimura, and simply watched as the girl, who had grown from a young lady into a proud schoolteacher, sat at the entrance of his house.
Finally, after much patience, Kiritsugu got what he was waiting for. Acht had sent Sella and Leysritt to gather information from Taiga. Naturally, Kiritsugu found them, naturally followed them, naturally discovered the Einzbern's new base, and naturally—
Well, here's where things stopped being so natural. Knowing that his daughter wouldn't give up her status as a Master and that Acht had summoned the great hero Heracles as a Servant, Kiritsugu couldn't just charge in recklessly.
What he needed to do was to carefully investigate the perimeter of the bounded field, gather as much information as possible, and formulate a workable plan. This cold, calculating rationality was precisely why Kiritsugu had been able to overcome stronger opponents in the past.
At this moment, Kiritsugu was unaware that Shinji had also found the Einzbern base and was planning on taking swift and decisive action to eliminate them once and for all.
About halfway through his reconnaissance, Kiritsugu noticed the bounded field shake. Someone was using brute force to break it. This discovery excited him; he knew this was his chance — a perfect opportunity to fish in troubled waters.
With the bounded field under attack, the base's alert and defense systems would undoubtedly be at their lowest, making it an excellent time to conduct a deeper investigation or even assassinate the Master. These were tasks the Magus Killer excelled at.
Having made up his mind, Kiritsugu cautiously infiltrated the area, carefully choosing a route through the less-guarded rear of the mountain. Every step was taken with extreme caution. After years of operating in war zones, he understood the importance of being careful and not overreaching. If he could gather useful information, that would be great, but if not, it was no big deal; there would always be another chance. His life no longer belonged to him alone — he had a wife, a daughter, a foster mother, and a step-sister to look after.
Step by step, he advanced, testing the waters. Neither the destruction of the bounded field, the collapse of the villa, nor the strange phenomenon of a solar explosion in the sky made him change his approach. Instead, he became more cautious. Without a monstrous-level Servant to guard him, a single mistake could cost him his life.
After getting close enough, Kiritsugu found a safe spot to observe. He didn't proceed any further, instead using binoculars to monitor the area around the villa.
The earlier disturbances indicated that the intruder was exceptionally powerful, so powerful that they had torn down the workshop despite the Einzbern's advantage of the terrain. In such a dire situation, as long as Acht had any sense left, he would surely decide to retreat. The invader had come from the front of the mountain, so the best escape route would naturally be the rear, where Kiritsugu was positioned. All he had to do was wait patiently like a hunter lying in ambush.
Of course, there were other possibilities: the invader might be so overwhelmingly strong that the Einzberns would be wiped out, or perhaps Acht would make a desperate, last-ditch counterattack. But both of these scenarios were unlikely, and even if they did occur, Kiritsugu would be able to pick up on some clues — the villa was no longer usable. No matter who won, they would eventually have to leave, so there was no need to act rashly.
This judgment was undoubtedly correct. After a few minutes, someone ran out of the villa. The unmistakable white-with-gold-trim outfit of the family patriarch told Kiritsugu that this was his target: Acht.
Still, Kiritsugu didn't immediately draw his gun. He hadn't yet confirmed whether Acht had any guards left.
Moreover, Kiritsugu's heart wavered. After all, it was this old man who had brought him and Irisviel together. Was it right to end his life so unceremoniously?
While hesitating, he continued to follow and observe.
Once he confirmed that the old man was indeed as helpless as he appeared — no guards, limping along with injuries — Kiritsugu overheard Acht's unhinged monologue.
At that moment, Kiritsugu made up his mind.
He stepped out from the forest where he had been hiding, facing the old man he had known for ten years.
His resolve to kill had not wavered, but at the very least, he would say what needed to be said before he pulled the trigger. He would let the old man die with clarity.
After saying a simple "Thank you" and "I'm sorry," Kiritsugu drew his handgun from his coat.