User blog comment:FairyRaven/Fairy Tail Chapter 375: The Supernatural, Review and Commentary/@comment-24536822-20140314141913/@comment-7418318-20140314142653

That he can use it at will, like Natu, is a possibility, but it's also possible that he can only shoot out the energy he absorbed from Natsu, similar to how Natsu wasn't able to retain the Flame God Slayer Magic and it was gone once he had used it up.

We'll have to wait and see.