Sakumura had the aptitude for the Saber class and could also be summoned as a Saber.
Sakumura, when summoned as an Assassin, was in a younger form, his personality somewhat more lively than in his deathly quiet old age.
But Sakumura, when summoned as a Saber, was in the state where he had fully attained mastery of the sword through his own understanding.
Sakumura was not someone obsessed with pursuing the sword. To him, a sword had always merely been a tool for forging ahead. After returning from Ezo, he had not even touched a sword again, only hanging one on the wall and no longer reminiscing about those bloody years.
The "mastery" he spoke of referred to his state of mind.
When that state of mind was applied to swordsmanship, it became Saber Sakumura's [Way].
But.
Sakumura was indeed an Assassin now, not a Saber.
An Assassin who had also lost one of his three Noble Phantasms.
"Let's investigate Saber's former base first. Though I'm guessing that even if Emiya Kiritsugu has left, he would have set up all kinds of traps and other messy things before he did. Assassin, be careful."
"You see things quite clearly."
Sakumura smiled.
"Don't worry. Traps can't possibly work on me."
"Then stay in contact at all times."
Whoosh—
Sakumura leaped out the window and vanished into the night in an instant.
"Saber Anno, huh."
Kirei Kotomine sat back down, picked up his bowl of sake, and took a sip.
But that was not what he was truly thinking about. He knew that, regardless of victory or defeat, Assassin longed to fight that opponent.
If he won, Kirei would gain the right to obtain the Holy Grail.
If he lost, Kirei could enjoy the supreme happiness brought by Sakumura's death.
What concerned him