"I'm not the only one being stupid." But that's all the argument he's about to bother with for Souji's position, because - stupid as it is, there's something more sinister behind this, and he doesn't think mere words are going to be enough to turn the tables now.

He turns, slowly, keeping himself facing Souji and hoping nothing or nobody else sees fit to interrupt this moment by taking advantage of his back...though maybe it would be better if something else did. As embarrassing as it is for a samurai to die to a back attack, the idea doesn't make something in his heart knot up uncomfortably like the idea of dying on Souji's blade does.

(But it doesn't matter, because the alternative is leaving Souji, and he's had enough of leaving people behind.)