Yeah, I was trying to remember anyone from the past who might still remain to hate Gray, but I can't think of anybody. Was it ever told what kind of a man Ul's hubby, and Ultear's dad, was? You'd think Ultear would have sought him out if he was still alive or anybody relevant.

In any case I don't expect he will find much luck in trying to keep Natsu frozen. But on the other hand Natsu is pretty reckless to attack the enemy stronghold alone.