Daria, is one of my new favorites.
She has one of the best abilities in any of these gacha type games, Ignore Defense! You do not have to worry about Defense Break with this young lady. Every 12 seconds she can drop some 100% ignore defense goodness.
The best way she can be built for PvE will make her a glass canon. If you plan on using her in Arena then you want to make sure to get some HP% and DEF% substats as she will not live long enough to be useful and with both stun and mortal wounds you want her to live.
Daria is one of the best technicians with a solid kit. I recommend her for those looking to take their game to the next level. She will serve you well in both Arena and PvE.