User blog comment:Linathan/Unit Spotlight: Cyclonic Blades Dion/@comment-26258826-20150709141654/@comment-26140304-20150710030954

It all depends. Narza doesn't attack, but he does provide the BB regen when attacked buff on his SBB and provides status immunity for 3 turns on his BB and SBB. Shera, on the other hand, attacks with her BB and SBB, allowing you to effectively drive your BB gauge momentum better as she has the highest hit count out of all of the mitigators released today.

Overall, Shera is used a lot more than Narza nowadays. You rarely see him get used.