Just a thought I had, but..
Primals need faith and aether to manifest, right?
And since what is summoned is mostly shaped by the needs and hopes of the ones doing the summoning (through prayer and the like),
they basically influence what sort of being manifests (like how Shiva was Ysayle's idea of her and not how she originally was during her lifetime).
So I wondered:
The main problem with Primals is their hunger for aether. That's the main reason why we fight them and negotiate with beasttribes, to stop them from sucking the planet dry.
So, is it at least theoretically possible to summon a primal that is NOT hungry for aether? Since the hopes and beliefs shape the primal, after all?
Like, for example, if my cult of Nymeia was absolutely convinced she is 100% benefical and in no way hurting the planet,
if we summoned her with a few truckloads of crystals and our faith, would she not suck up aether despite staying in this world?