Not for a lack of trying.

[ There's no real resentment there, he simply says it as it is. Twice she tried to kill him, once before she finally gave him back his name, and again at the end. Moreover-- ]

Or for accidents. If not for Rosiel's blood, my soul would have been lost when my blade shattered. Tell me, what was it that convinced you I was such a threat to Setsuna?

[ It's ironic to him that Setsuna's faith in him should be so unshakeable, but he never seems to have had it from her. ]