Considering a thought which was given here - about making late-game LESS dependent on SCs I would offer to include some positive-event, etc. spells. I remember that somebody did include something like that in his mod using #copystats to gain positive-effect ability from existing Pretenders, than making new creatures immobile and non-attacking & naming the Menghirs...
There is also a possibility to include a Mountain That Walked as a Nature summon - a particularly large & wise elephant. This creature was known for his habit of making a regular ambushes against hunters who tried to shoot him.
Maybe he should even be a mage - though with research penalty.
Considering a bear-spirit having an access to Death - in North Asian folklore, at least, bear was considered to be a very wise animal, having an access to spirit world...