Why did Yoru Machi want to involve himself in the Fifth Holy Grail War? On one hand, it was because he had already obtained what he wanted.
On the other hand, compared to the Fourth Holy Grail War, the Fifth Holy Grail War was practically one enormous family melodrama.
It had been fine when the original plot only included Souichirou Kuzuki, but now look at who the participants in the Fourth Holy Grail War were.
Leaving aside those farther away, among the Masters currently gathered at the Matou Family, Rin Tohsaka and Sakura Matou were sisters, while Shirou Emiya and Illya were siblings. One was Irisviel's adopted son, while the other was her biological daughter.
Kiritsugu Emiya was currently holed up in Ryudō Temple with Sasaki Kojirou, but there was no need to elaborate on his relationship with Illya and the others.
In the entire Fourth Holy Grail War, there were seven Servants and six Masters. The only ones hurt were the Mage Killer Priest and some loser dog from Cú Chulainn; everyone else was basically family!
Irisviel wanted to tell Illya how important Yoru Machi was to her, as well as some things about herself, but the current setting was completely unsuitable. She could only take her daughter and prepare to head home.
When Shirou Emiya saw Irisviel preparing to leave, he finally gathered his courage and stepped forward to speak with this adoptive mother he had met only once.
Previously, Shirou had not understood why Illya knew him and harbored such intense hostility toward him.
But the moment he saw Irisviel, Shirou understood everything.
"Mother..."
"Don't force yourself. Calling me Irisviel is fine. The one who adopted you was Kiritsugu Emiya, and I never fulfilled any responsibility in raising you while you were growing up, so I don't