Hi Zerakon
To get a speedy take on how the LA game system operates, go on over to www;lejendary.com and download the free pdf there, LA Game Quickstart. It is a complete, self-contained adventure that needs no other LA game material to GM and play--pre-gen Avatars for six players are included.
Thanks for the compliment about adding something to your campaign, and your post came when I am in the midst of compiling supplemental material for the LA game, getting it organized and into shape for publication as a book, so my mind is rather stifled in regards to creative additions to an adventure
The trogs must have a master, and maybe it's their "priestess," a hag of some sort. Their place is likely near water, a marsh of the like, as indicated by your mention of the villager being transformed into a swamp beast. If that fits, perhaps the hag is planning on changing a number of men into such creatures to form a sort of harem for herself. Of course she'll then aim at the PCs for the same reason, wishing to make one or more into "handsome consorts" for her when she returns to her native habitat. The trick will be to convince the trogs that the had is duping them, not really helping them at all, save to endanger the trog community by her antics. That's off the top of my head FWIW.
Anyway, I have done a fairly recent dual d20/LA game system module, THE HERMIT, that is available from Troll Lord Games. The Trolls are now in process of editing and laying out a vast super-module I've written, THE HALL OF MANY PANES. that will likely be a boxed product with two large books in it, as the adventure will take about a year of normal play to complete. Ot is also slated for dual system presentation.
Cheers,
Gary