I hope Kiera doesn't get a complete overhaul. Buffs I would like to see are things like -turn CD for her elementalist. Since just about every mystic has paper defenses, I think letting her survive for 7 turns is too long. What if you cut that skill to 4 turns and maybe take the numbers to ~70% efficiency compared to the original(her 160% dmg on cast become 100-120% while her burn becomes 70% per tick). Her aura is already good for a mystic lineup so trying to get her by for 4 turns will be a much easier task compared to trying to keep her alive for 7 turns. By cutting it to 4 turns, i think Kiera Ele could now contest with Talissa because she's honestly just so good as a mystic.
Her mind warder maybe should get the Zoey treatment. Give her aura a stun even just a 1-turn stun to prevent archer trigger attacks. Her skill would also appreciate an additional debuff(like an AOE ATK reduction).
I honestly think her Kiera RM is the closest to viable but as a valiant, she's underwhelming. I feel just a CD reduction to her skill and making it a missile would make her powerful and tanky for mystic standards, at least.)
Her warlock route would be amazing if her skill was at 5 turn CD and adding a bleed would make her disastrous to face against. That means at wave 2, she can potentially destroy formations on top of the damage which is incredibly crucial for some lineups like trigger lineups. Her aura needs an additional debuff, as well.
Better yet, give all Kiera routes an on-spawn skill that can help them breeze through a few turns.
Just my two cents. I hope she becomes close in power to Zoey. She doesn't need to be as strong but she should be up there.