That was a relief, it really was. Holding on to the particularly painful what if I hurt her more would, Loki was fairly sure, have inhibited any chance of actually getting things right. With Thor there, he could and did let it go.

Loki took a deep breath, closed his eyes, rested his fingers as lightly as possible on her injured torso. There would be some added pain for her, but that was inevitable. He pushed away upsetness about that, and started weaving the spells, as Frigga had tried to teach him so many years ago, to knit flesh and bone together, tidy blood back into its vessels, all of that.

It had never worked, ever, not really. Small wounds of Thor's, on the third or fourth try, yes. And then Stark, once, in a moment of total desperation. He was less desperate now, but need had worked before, so Loki used it again. He needed Valkyrie to be healed.