Glaciela (Regalia) is a cost 100 magic damage dealer that's all about bursts. She has a whopping +50 magic ATK buff (Rally Magic), and a wide explosive area damage (Grand Explosion) that essentially ignores enemy SPR. But for magic resist piercing, she'll have to rely on other sources like main job as the sub job, her own TMR, or Peacetime Brooch.
Her sub jobs are all actually worth looking at, since they're not just there for the passives and can potentially change her playstyle. Main job as sub job is her only way of reducing enemy magic resist. Scholar sub has Law of Speedreading to make most of her spells close to instant cast, while White Mage is the usual healer role. No full life, but she has Raise.
Compared to Helena (Black-Robed Witch) (another cost 100 magic damage dealer), Glaciela has the "same, but different..." feel to her. They are close in many ways, but Helena being a Dark element and have ways to reduce enemy resistances + a guaranteed hit ability gives her a noticeable edge. Glaciela still does a good job of being a damage dealer, just in a different way.
It's worth mentioning that even though she's a cost 100, her shards cost about the same as any other units, so she's not more expensive to raise compared to other units. However, daily shard quest is still only once a day for them.
Im currently at chapter 13 right now, but as the story goes it seems either she will try to 🔥 Mont on sheer confusion, or try to be reasonable but cant marry Mont now, because she is a rebel noble... Things are not looking good, Graciela bros...