I tried modding my suggestions, but using Seasonal Spirits and CB together leaves them without magic.
Any suggestions for the great bear spirit of autumn? He'll be E4N3D2 at least, 200 hp, ethereal, prot 30, regen 20 and will heal his afflictions. And fallpower 50, so that his hp fluctuate between 100 and 400. I think he's the weakest one of the four because he doesn't have any AoE effects, damage shields or weapons, and the others summon better helpers. Would trample and 20 AP be enough to keep the bear competitive in the late game? I could give it some reinvigoration as well, if necessary, and it will have magical claws and bite to use against anything too big to trample.
The other ability I've been considering is huge fear aura, and an undead secondshape to protect him from soul slay. It'd link well to the Finnish peijaiset ritual, but also mean that he coudln't handle chaff alone.