Her first reaction is, quite naturally, confused shock. Because that is very much paper and he is very much doing... whatever it is, to make it do...whatever it's doing. So he talks and she lets the concept of studiousness cover her wary glance. Shepard doesn't consider herself to be a particularly smart person, but she's known many geniuses, and whatever else was true it'd been good practice for keeping up when you knew approximately fuck-all about what someone was saying.

So it's a moment's consternation for the paper magic, and then it's down to brass tacks, crouching down to join him in the dirt. The method she might not know, but his purpose? That's familiar. Anyone can understand a need for decent crowd-control tactics.

"So it's like a Barrier... Is this a common problem, for you?" He says corpses, but she reads it for Husks. Shepard can understand the need to throw off a pack of husks: they weren't hard to deal with in ones and twos, even as many as four could be called manageable. But you count on your fingers how many times that few would be all you had to cope with and never need a second hand, "What do you consider to be a 'large' group, we talking six or more?"