It takes Erik some time to look up from the deer once Ned's touch has gone into it; he's felt life leave enough bodies to know that that is authentic, rather than the way he had to touch to confirm before. Ned's somberness doesn't tamp down his fascination much - it would someone like Charles, he knows, Charles would be sensitive, would say the right thing - which is just one of those things he comes by honestly. He understands the weight of life and death, but while his relationship to those ideas (especially the latter) is certainly unique, he doesn't feel it the way Ned does.

"If it worked more than once it would be trivial."

Mostly this is thinking aloud, Erik obviously turning the words over in his mind and mouth as he forms them. By this point though, he is considering Ned with much the same affect. "You do realize by now I don't often bother with politeness? By the same token it follows I don't make threats."

...it seems fairly likely Ned has gathered that, yes. Just scary, scary promises. He lowers the now cold body of the deer back to its position on the tarp and brushes off his hands; he's not markedly perfunctory, but there's no ceremony in it either. "When I said I was interested in a demonstration that was exactly what I meant. Not 'demonstrate or face the consequences.'"

His eyes flicker back down, black lashes covering them as he marks the outline on the tarp, the subtle ways it changed in that brief moment of life. "You have an extraordinary gift."

Speaking of just saying what he means; the repetition is obviously deliberate. "But it's not one I would have forced you to use."