User blog comment:IamJakuhoRaikoben/Chapter 330: Zirconis' Magic, Review./@comment-5580383-20130512023446

"Mirajane would never get one shotted. I don't know why everyone assumes that she's useless without employing Satan Soul. What S-Class Mage of Fairy Tail that you know has no endurance or durability? None. Mirajane is a very powerful Mage and she's underestimated because she has a nice personality. Personality has no bearing on strength. Keep that in mind."

Agreed, didn't Mirajane  kick  back Azuma  within base state and surpised him with her speed and power whereas Pantherlily ehanced with Wendy's magic who was on par with Gajeel couldn't even lay a hand on Azuma ? Also didn't she recently held her own with one of the Garou Knights in base  but completely curbstomped  them with Satan Soul.

Still Mirajane would defenitly need Satan Soul against any of those dragons given they're on par with Ancologica holding back.