The Summoner needs a lot of changes because its structure is completely unsuitable and excessively rigid.

Yes, it would be nice if they added Shiva, Ramuh, and Leviathan, but above all, I would like them to rework the gameplay.
It feels slow, stiff, and bland, and it's a shame. I still don't understand why they haven't reworked the resource management system—Energy Drain is a relic of the old Summoner that I find completely absurd in the new gameplay.

Personally, I would like them to restore each Demi’s identity, making them a kind of mini-game with a unique passive effect rather than just pressing 1111 and getting an AoE heal that stays available for 30 seconds on Summon SolBahamut.
Maybe it's just copium, but I wish they would make them completely different from each other—not just in terms of spell power, but at the very least in terms of effects and gameplay.

I also want elemental summons to be better designed.
Right now, they feel meaningless and have no interactions between them that could add strategic depth, such as an elemental combo system—especially if they add three new summons.

I’d love for Carbuncle to be useful again.
For example, it could store Aether for the Summoner and provide one stack of Aether every 20 seconds, which could be used for Necrotize or Painflare in combat, with three stacks available at the start of an instance.

I would also like elemental summons to become OGCDs and for Carbuncle to get actions similar to Egi-Assault 1 and 2, giving two stacks each (counted as spells for weaving) with a 30-second recharge per stack. After using all four stacks, Carbuncle could temporarily evolve into Proto-Carbuncle, allowing it to freely use "Radiant Shield," which would reflect a portion of the damage dealt to party members as potency-based damage.