User blog comment:LastationLover5000/Fairy Tail 353 - The Dark Magic's Purification/@comment-4728047-20130929011437/@comment-4072803-20130929032222

Well, what if in a super major duper super plot twist, Ur/Ul had been teaching Gray Ice Devil Slayer all along under the guise of ice-make, which might explain how he can utilize basic ice magic (like redirecting the ice against the demon and freezing that Eisenwald mage), and it was revealed to him in the future so he went evil just cause.

-Hiro's writing style.