Gray Fullbuster and Juvia Lockser are in a very tight spot. Invel placed collars on them, attached together by a chain, and they have no choice but to fight each other to the death. In "Fairy Tail" Chapter 499, the battle ensues.
As previously reported on Asia Stars News, "Fairy Tail" Chapter 498 showed Gray's fight against Invel. Natsu managed to melt the ice that froze him, Lucy, Happy, and Juvia, but the first three were taken away by Brandish. Invel then forced Gray and Juvia to fight.
At the beginning of Chapter 499, the two Fairy Tail mages refuse to hurt each other but Invel's powers, using the collars and chain, reduce them to puppets and they cannot control their actions. They attack at the same time and, as the fight progresses, Gray proves to be more powerful.
Invel wants Gray to win since killing off a friend or ally will bring out his darkness, which Invel believes would allow Gray to defeat E.N.D. With E.N.D. out of the way, his master Zeref will be able to defeat Acnologia and rule the world.
Juvia, meanwhile, is struggling within herself - she does not want to fight against Gray but losing to him means he would blame himself later on. She decides to just end her own life. With sheer determination, she stabs herself with an ice crystal and this surprises even Invel. But the chapter shows that Gray had also stabbed himself at the same time she did.
Invel is horrified by his miscalculation and is confused by their decision. He walks away thinking that he has to be the one to defeat E.N.D.
As the blizzard subsides, Gray is surprised that he is still alive and senses Juvia's blood inside him. The water mage had apparently prepared for the worst case scenario. Having perfected her Blood Transfusion magic (since blood is made primarily of water), she put herself inside Gray to save him. The young man is devastated and begs her to open her eyes.
Meanwhile, as Invel follows the direction Brandish took, he meets a serious, furious Gray.
The "Fairy Tail" manga is on its way to its 500th chapter. Given that its title is "Fire and Ice," it can be speculated that Natsu will be joining Gray in the fight against Invel. Yibada says that learning about Juvia's sacrifice will make him assure Gray that the Winter Mage would die.