Gray knew that they were losing, he also knew that this spell, Memory of Death would absolutely destroy (consume) the pair if he did nothing. He remembered listening to Erza one night (when surprisingly she had gotten drunk) and he knew what transpired on top of the Tower of Heaven and what Natsu had done to achieve the epitome of his power.

He also remembered seeing his rival rise up to the challenge of being strong to protect his friends on several occasions. One that was vivid in his head was the incident in Galuna Island, he had watched his rival *cough* friend *cough* prevent Gray from sacrificing himself to save his friends despite the fact that if Deliora had been at full strength Natsu most likely would have been crushed like a bug.

And then the momentous occasion in the Grand Magic Games where he had taken on two dragon slayers who were newer generations by himself and done the impossible and won.

He also knew that Natsu was fuelled by emotions and the desire to protect those he cared about and - not that he'd ever admit it out loud - he knew because of that Natsu was the stronger of the duo, sure he could definitely hold his own against enemies, especially if his friends lives were in danger but Natsu was a constant burning ball of emotion that was fiercely protective.

So when Mard Geer raised his hands a need to protect Natsu rose up inside of him. Gray had to allow the slightly younger boy to destroy the leader of Tartaros, he believed in him. He was putting his faith in Natsu, he could not fathom to believe that Natsu would fail, he simply couldn't.

As the spell raced towards the duo, consuming their very essence Gray raised his hands defensively and pushed the magic gifted to him by his (now dead, it's all your fault) father and willed it into a spell that would undoubtedly protect Natsu from the brunt of the attack.

As the smoke cleared and Mard Geer resumed his more human form and finally finished his monologue. Gray felt air rush over him and an intense but controlled heat let him know that his best friend was still alive and breathing.

Gray relished in the surprise that appeared on the demons face and with that he slumped, he was completely exhausted after that magnificent display of power. Not that he knew it but Gray had just willed his inner demon to obey him and that alone should have been impossible for a slayer of that age.

But even as his eyes went to close he watched Natsu fight the current leader of Tartaros, Gray felt some grim satisfaction as he realised he was completely right. Natsu's rage at Gray's fall had stoked his fire and made him push past any injuries he might have sustained during the fight.

He was also a little bit terrified, Natsu, with this power at his command was a force to be reckoned with (even though he would never use it against his nakama). But even with the new power brimming out of Natsu's body it wasn't enough, Gray frowned, Natsu's power was beginning to wane and he could not allow such a thing to become the source of the dragon slayer's death.

Gray pushed himself up despite the pain coursing through his body at every slight move and settled into a position that would allow him to attack, he formed the last of his energy and strength into the destruction of Mard Geer.

He almost smiled when he heard Natsu say "But I believe too. Gray!"

He pointed the bow moulded from his Devil slaying magic at the demonic form of Mard Geer and fired, screaming "Ice Demon Zero's Destruction Bow!"

And it was over, well not the fight with Tartaros or FACE or END, but the current leader of Tartaros had been defeated.

For now, he simply looked at his rival who had developed into a very close friend and smiled at their relationship. Natsu looked at him too, there was none of the usual "hate" that accompanied those olive orbs, instead it was appreciation.

Natsu was leaving, he knew this, and Happy knew this. Lucy would soon know but there was one other person he had to say farewell to.

So here he was, Natsu was going to drop by ice block's place first, after everything that had happened between the two during their first meeting and Mard Geer, well, Gray deserved at least a brief explanation from the pyromaniac.

Natsu whistled with his hands on his head, walking the path that he knew would take him to Gray's apartment, sure he had never actually been there, that would be weird, but he still knew where it was, that statement was reinforced by the scent of Gray (pine cones and oddly enough berries) permeating the path.

Happy was walking beside his owner, salivating over the thought of all the juicy fish he could find when they were away.

Sure enough, the apartment that belonged to Gray came in view and Natsu, with absolutely no finesse burst inside.

"What are you doing pyromaniac?!" Gray yelled, jumping up from the lounge he had been sitting on.

Funnily enough he was already half naked and had settled into a stance that promised ice. "Whoa! I'm not here to fight stripper." Maybe Natsu should have knocked, whoops.

"Gray!" Happy shouted and immediately launched himself at the ice mage and into his arms.

"Well, what brings you here if you're not here to fight? Actually, how did you even find here anyway?" Gray asked internally groaning.

"I followed your scent of course!" Natsu yelled as if it was the most obvious thing in the world. "And I also know where your home is."

"How did you…? You know what, never mind that, why are you here Natsu? I assume you didn't come here to be all mushy with me." Gray commented looking expectantly at the boy.

"Wellll, I just came here to tell you that I'm gonna be gone for a year, off to train and become stronger than you ever will be, and when I get back imma kick your ass!" Natsu grinned at the stunned devil slayer.

"You're leaving!?" He shouted, looking just a teensy (okay a lot) upset by the idea.

"Yeah, I'm gonna become really strong in a one year training trip. No-one else is coming with me aside from Happy but I just wanted to let you know that you should train too, wouldn't want it to be easy to kick your ass." Natsu said, ignoring all of the other things that he could have said.

"You better not get another rival, I'm still your rival."

"I'm still coming back droopy eyes."

"You better take good care of everyone Gray, I'm counting on you." Natsu said smiling wider. "Oh and tell Lucy that I'm sorry, I've already written her a letter and it's the next place I'm going to but she might come after me, if she tries that make her listen to reason k?" He asked, eyes wide and trusting.

"Sure, but I don't really know why you would come to me..." Gray said tentatively.

"Eh, well, Erza would probably force me to stay through brute force and the rest of the guild aren't as close as you and I are to Lucy." Natsu replied.

"Sure flame brain." Gray said smiling. "One more time?"

"Sure, for old time's sake." Natsu said grinning. "Happy, take us to a small clearing."

After everything was said and done Natsu smiled wider and said to Gray. "Don't die."

Gray's eyes widened in shock, "So you did hear me all of those years ago. Huh, well, in that case don't die, it'd be weird without you."

At the sight of Natsu's fist Gray bumped it, hard. "Welp, I'm gonna go give the letter to Lucy, see ya in a year Gray!"