he's heard that it likes to hide in the trees, moving between them, and that it hunts at night.
Sounds annoying. If it travels through the trees and doesn't just hide in them, then that might present some difficulty with tracking--though Zamia might still be capable of it. Hunting at night is a more major concern, simply because it might mean
even more waiting, and it might attack when people are asleep. Someone with decent will should always be a sentry at night, else I fear one of the Alkahest hunters will get mind controlled and just start slitting throats.
They haven't seen the lost caravans either, only have reports of what locals found. They reported that the boats the caravans were on were overturned. Bits of the cargo were found down the length of the river and the bodies that they DID find seemed to be the victim of either a creature with great scything claws or a blade. The leader of the team says, under his breath, that he half expects this to be the work of some group of bandits using the "Tree shadow" as a cover.
That doesn't sound like something one of the gorilla creatures would be capable of, and the Boneless hunt near caves--not rivers. The fact that the corpses look like they may have been killed by people also lends support to it being a Predator Saint. Bandits seem doubtful--they'd have put a fair bit of work into making things look like an animal attack, at the cost of capturing usable boats and a ton of cargo. That doesn't strike me as a wise plan, on top of conservation of detail making bandits very unlikely.
Really, I think it might be a decent idea to just ditch the Alkahest hunters, possibly even splitting up further. The beast supposedly doesn't ever fight on its own, instead just mind controlling people--those hunters are likely much more vulnerable to that than our hunters are, and might end up needing to be executed (which would also look bad for us).
On the other hand, the creature was described as gaining power over time, eventually being able to send cities into chaos, so perhaps the hunters would act as ablative mind control protection; it could get two of us, or four of them, so traveling in a group reduces the overall percentage of power that it can control.