Hanna built to be the rapid s atk spammer.
Her basic atk mode gatling is quite plain, but it fill her gauge very fast which is responsible for her s atk spam. Her s atk is mode orbital laser which target a row of enemy. Unfortunately in exchange of rapid satk spam, it have quite low damage compared to other row targeting s atk. Thus despite she was good as mission mob cleaner, most unit in arena will more likely survive her atk and gain gauge for being attacked.
Her secondary atk mode laser have the same "not enough power" problem as her satk counterpart. That means free gauge filler for everyone.
In addition of that hanna have quite a low survivability. Making her very dependant to other support unit. Ideal partner for her is soyuz with ignore atk shield satk and def unit with taunt all such as bibi and sella
She is good mob sweeper in mission stage but rather poor to be used in arena. The only good possition for her is behind the front line
As mentioned before she is rather poor in arena and for most of the time will be stuck behind the front line. Just bring a sniper or row atk unit and she will be toast