Suzune Amano

Strong Connect

Suzune is an attack type unit, so she has great attack stats and she has the added advantage of three Accele discs (much like Rena Minami). Her connect increases damage as well as increasing critical hit chance so she can really boost the attack power of common magia building teams and works well as an attack unit in non-blast oriented teams.

Powerful Magia

Suzune's high attack and the fact that her magia hits all enemies on the field allow her to deal out significant damage to all enemies and take large chunks of HP from multi-space bosses. It also grants the burn status effect for added damage at the end of the round.

Glass Cannon

Since she is an attack unit, the trade-off is she has rather low defense and HP stats so she may die easily unless she has multiple slots or some kind of tank unit to take the damage for her.  Otherwise teams of five would be best.

Strong Connect

Suzune's connect has a 70% chance of critical hit and increases damage by 40%. It's basically the connect version of "I Made Friends". However Suzune is also a glass cannon with lower HP and DEF, and may have difficulty surviving long enough to use her Connect at all.

Personal Memoria

Her personal memoria gives guaranteed critical hits for a single turn and has a cooldown rate of 6/5 turns, making it very viable for Mirrors should you choose to use her (and can keep her alive long enough to use it).

Triple Accele Discs

Having 3 Accele discs is not very useful in Mirrors, as it is still difficult to have a Magia ready before dying, and Magia damage is nerfed in Mirrors. 

Fire Element

Strong water element Magical Girls are very common in Mirrors, especially the likes of Yachiyo Naname and Nanaka Tokiwa after they get uncapped. This limits her damage output and means she'll likely be among the first on your team to fall. At best you'd be able to take down grass units like Mami Tomoe or Alina Gray with relative ease on the first round which would ensure the longevity of your own water units.