[Matsui had been in the midst of some prayer or another, but is paying enough attention to his surroundings by now to notice another person's arrival. It's familiar, and his heart wells up with too many emotions for him to make heads or tails of.

He remains silent for a few moments, hands still clasped together, the knuckles of his exposed hand going white.

But eventually:]

...You have taken Rin's life, and with my actions today, I have helped to take yours. It is a weight that I will be sure to carry.

[He doesn't take the trade or barter of lives lightly.]