Fans just witnessed the much-awaited E.N.D. awakening of Natsu Dragneel during Fairy Tail 503. This part, however, as theories suggest could be a pivotal moment for NaLu shippers.
The battlefield has descended into chaos, starts Fairy Tail 503 while Natsu and Lucy were shown still tied up -- the former unconscious while the latter is trying to break free from the chains. Dimaria appeared, mocking Lucy's pitiful condition and further toying with her by stripping her out of her bra. As Lucy complained, Dimaria said that she would also strip Natsu so they'll be in "the same boat." Dimaria then turned to the unconscious Natsu, grabbed him by the head and pointed out that he might be dead already considering that he's barely moving, much to Lucy's disbelief. Dimaria noticed Lucy's huge eyes and thought it would be a good idea to gouge them out. Just as Dimaria was about to plunge the knife into Lucy's eyes, Lucy screamed "Natsu" or rather think about Natsu, the frame shifted into an unconscious and naked Lucy lying on the ground.
What happened after was an untold battle between Natsu and Dimaria. After Lucy regained her consciousness she found blood splattered on her face with Natsu nowhere to be found and Dimaria all beaten up while muttering "Monster." While Hiro Mashima left this unsaid, this could only mean one thing, Ethereal Natsu Dragneel has been awakened.
Natsu was later shown looking for Zeref but bumped into Gray instead. Fairy Tail 503 ended with the afterwords, "Their two fates, while being strung along by Zeref will now violently and tragically clash," hinting that a major battle between Natsu and Gray might possibly happen in Fairy Tail 504.
