User blog comment:IamJakuhoRaikoben/Chapter 458: Morning Star, Review./@comment-96.24.244.24-20151026174451/@comment-5894890-20151026180519

As for your 4th point this is how I see it. She basically drenched the sand, making it soggy and clumped (not necessarily hardened like she says), which disallowed any dry-sand to erode at her blade; allowing her to slash Ajeel.