How I would see summoner - you have your skills - some are pet specific some are your specific.

You would have the pet out as is an egi - a primals essence in a form.

But then you would have pet skills that once activated would for a short duration force the pet to become the primal in your thral - maybe not a 1:1 scale but a mini version - you are only one person so limited aether.

So you would trigger titan egi's landslide - pet suddenly becomes titan and slams his fist into the landslid attack - knockback and all.

And it would be micro managing all of this that would be the core of the gameplay.

I would also add that in addition to that you would in the end have 3 primal essences floating around(1 for each aetherflow stack). And you could use any of their attacks that way. Out would go the whole dot management and other such things. In would come full blown pet management.

Each pet would have more or less all the primals attacks.