Let's see what Shade thinks. I get out of my depth with these epic critters.
Hehe. But we're talking about the Tree of Wailing Souls here, which would be a pretty neat capstone encounter for a campaign ending in the upper teens. Or maybe just a pre-BBEG encounter.
How about CR 22?
Let's go with that and see if Shade objects.
Treasure sounds like a lot from the description. How do you like triple standard? I'd be willing to go down to double.
It seems to have an affinity for magic items, to be sure, but the detritus of centuries' worth of adventurers ought to be lying around in its roots. How about double coins, double goods, triple items?