Now we believe really hard that a handful of dust is going to prevent this thing from killing us would be accurate but also the least confidence-building answer Stiles could give, so instead he darts forward long enough to complete the mountain ash circle and then shuts his eyes for a few seconds while he does the whole Imagination is the most powerful whatever step. It kind of sucks that there isn't an incantation or something to make him look cool for this part, but the important part is that it works, probably just in time because the kanima breaks free of the webbing enough to swipe a claw at Stiles that would definitely have caught him in the chest except that it runs into the invisible wall created by the mountain ash.

Stiles doesn't flinch back because, well. Absolute belief and all that shit. He lets out a breath, though, before turning his head and throwing a smirk in Spider-Man's direction. "We got it." Of course, there's shit they need to figure out now that they have it, but let him have a moment of triumph, please.