“You’re dead!” Naltine picked up the pillar at his side and swung it at Shirou. But the pillar went flying in the wrong direction, a single sword dropping to the ground where Naltine had once stood. This time, Yogiri was able to see what happened. Naltine’s body had turned solid, then compressed into the form of a sword before dropping to the ground.

“His level wasn’t too bad. He makes a decent weapon. But he doesn’t quite meet the threshold of being a rare item. It’ll probably do as a somewhat expensive sword at a shop, though,” Shirou mused, picking up the blade that had once been Naltine.

...

“Whether they are sold or not, I have no idea how he did it! There is no way to defend against an attack we cannot even perceive!”

Though Tomochika and Atila seemed on guard, Yogiri didn’t feel threatened in the least. While turning someone into a weapon didn’t necessarily count as an attack, Yogiri couldn’t imagine it as anything else. If Shirou tried it on Yogiri himself, the Sage would instantly die. It was the same as anything else.

-Volume 13 pages 25 and 27