ill be honest: a pet system is not needed at all. having more than your heroes to control is no fun. i mean, its not like its too hard or anything but seriously, its just no fun. who uses summoning spells? they are boring and they dont scale on items anyways.
what we need, what we REALLY need, is TONS of bugfixes, items not working, games crashing and worse.
after bugs have been fixed so its playable without getting completely
**** at some points, then you can work on adding new stuff.
and i think the espers are enough of "pets" really. you can make them scale into lategame better and you can make it so you can customize your espers, level up and/or chose their skillset or whatever. that would be more fun.
i mean, i love your campaign but better make stable what you have instead of adding new stuff that'll have tons of problems aswell.
sincerely
CoNteMpT