Thanks for the welcome...though I’ve been about for a while now.
Oddly enough, even high level parties can be surprised if you play off of their assumptions. The idea that this is some excessively powerful fey with unusual and unique powers could wind up having them guess wrong, make an assumption or two, and then you’ve got ‘em.
As for the motivation...that’s actually intentional. Far too many villains are obsessively preoccupied with being villains. I was aiming for Erathagalis to be lazy and unmotivated...if anything, the Beholder Tree is him being on sabatical. I liked the idea that if the PCs were to drive him out without killing him, they’d actually make the problem worse.
Still...it won’t necessarially work for everyone, but motivations are easy enough to change to suit a DM’s needs. I’m definately glad you liked it!