"Saving all sentient beings" was the original purpose of it all, after all. But how do you do that when the environment is anti-everything? Only a fool would even want to apply absolute altruism, so this here sigil is for a brainless fairy who can do that. Maybe it's more of a fish which looks like a fairy.

The brain seems indeed to create evil, so the only way to make sure none is created, is to exclude the brain. The problem with that is that all development stops if you remove the brain. So this fairy/fish is created on the bold assumption that this form does not need to be evolved into anything, ever.

It does not have reproduction which adds anything to their genetics, it's just completely resistent to physical change. It allows spiritual learning and improvement but the physical is locked.

Even the worst of the worst, thrown into the spittoon at the bottom of non-existence, should feel attracted to this form enough that they rise themselves up, and it should contain them strictly enough that the only path is to climb up. Will this work? Well here it is.

If evil is "stupidly intelligent", let's leave that scale completely by making it non-applicable. Becoming automata may be the only salvation for some.