She didn't negate squat. Skullion was still turning his body intangible after her attack. He was turning his body intangible as Natsu was attacking him.despite my issue with the wording, it doesn’t change that she negated his intangibility that turned his entire body from ash back. No he was already ash when she used the spell. I am certain that Elfman can counter his ash body with his one of his beast forms, caught off guard is debunked. Mira is still stronger than Gray as of right now
So your argument for Mirajane being able to damage Skullion is to make up an ability for Elfman?
Yes, Mirajane is stronger than Gray for now. Like until he actually goes all out and beats Skullion, which he inevitably will.