It was not a fun thing to watch someone explode - well, scratch that, it was if said someone was a dirty rotten stinkin' human, but Jude exploded in a shower of Dark Magic that had coagulated like animal fat, which also meant that most of it splattered on Natsu and his open mouth. He wanted to throw up but everything that the magic touched turned cold and numb, and besides that, it tasted kind of sweet, strange as it was. He relished it for a minute before spitting it out, remembering where it came from.
"Is it just me, or did your plans blow up in your face?" he said to Mystogun, smirking. Mystogun focused very hard on the spot where Jude blew up. Natsu would've joked that he lost his marbles, but at that moment the building began to rumble and shake. His heart raced despite himself, which really didn't help his already-battered body. "What's going on?" he demanded.
"The spell is taking hold," Mystogun replied, raising his head to the ceiling. He closed his eyes, expecting the roof to cave in, but nothing happened; the rumbling stopped, even. He cracked his eyes open and found Mystogun smirking back at him. "It'd be smart of you to hold onto something," he said.
"What-" Suddenly, with no sort of warning at all, the entire room tilted at a forty-five degree angle. Surprised, he slid down the floor like it was oil-slicked and slammed into the wall painfully. His thoughts scattered for a minute, and when they came back together the room was level again. Mystogun hadn't moved an inch. "W-What's going on?" he repeated. He saw Mystogun roll his eyes right before the entire room went black. He at first feared that he was blind, but then he realized that somehow, the light Lacrimas had all shut off at the same time. Then, just as quickly, a hole opened up in the cement wall, and the best that he could describe what happened next was that the room spit him out.
He rolled down a long tunnel that smelled like earth before hitting some sort of obstruction that felt strangely like a big rock. He blinked; it appeared to be an underground dirt tunnel. He pushed at the ceiling above but it had to be at least six inches thick; a few clumps of dirt fell but that was it. He gasped and immediately regretted it; more mud went down his throat than air, which was very sparse. He coughed and gagged and realized that he had to way of getting out with human strength. Even though it would hurt like hell in the morning, he decided to turn into a dragon.
The shift was infinitely more painful in a closed space; it felt like the dirt was worming its way between his skin and burgeoning scales- actually, that may have been literal worms. He felt the pressure on his body grow as he did, his protruding reptilian skeleton grating against the rocks and hard-packed dirt; it was even worse when his tail tried to grow into the rock. After thirty seconds of grinding, groaning pain, the dirt began to give. He felt the unfamiliar-familiar sensation of sun on his back as cracks broke between the mud. He forced the change to go faster, which only exacerbated the pain as his face poked into a snout and his fingers curled into long claws. He felt the sun hitting his entire back at that moment and stood up straight; that was when he realized he and Mystogun had only moved to the basement of the castle, which was dripping with thick black goo like the stuff that was all over Jude. He fought the urge to go over and lick it as the transformation finalized.
The castle began rumbling again, but this time, since he could see it, it looked ten times worst. Then the black goo tore away from the building with a sickening sound like a magnified version of rubber boots in the mud, and it slowly molded into a long black-green tentacle. Several more tentacles appeared - seven more, to be specific - and three eyes appeared at random intervals, all brown and bloodshot and constantly constantly spinning. Natsu was glad he hadn't eaten anything in a while, because otherwise he would've been violently sick.
A window at the epoch of the castle had its glass explode out of the blue, followed by an ear-piercing shriek that made him want to curl in on himself. As he watched, several draconic, wyvern-like versions of the Nemesis demons soared out, circling the castle and creating bedlam with all of their crazy screeching. He watched as dark black-green clouds formed around the castle, booming and shuddering with sickly green lightning. Those clouds slowly propagated until they were halfway around Crocus; there was no way the people would get out unscathed at that point. He heard a loud roar as a grey streak zoomed past the clouds, headed straight for the castle. His heart leapt; Gajeel could handle it, he was a strong person. He'd handle that and Natsu could deal with Mystogun and Jude - or at least what was left of Jude. The castle saw him too, for one of its many weird black tentacles pulled back and swung forward; he spread his wings wide to halt himself, missing the suckers by centimeters. He didn't anticipate the demon that came and blasted him in the back with Fire Magic, or the other two.
"Gajeel!" Natsu shouted, spreading his wings and taking off. He flew under Gajeel as he began falling, and luckily managed to grab his arm and pull him away from the other battle-happy demons. "Are you okay?"
"No," he groaned, which just went to show how bad the situation was. "Those guys... Those guys are strong." Natsu growled when he saw that their attacks had cleared away a good handful of Gajeel's metal plates, leaving his skin bare and bleeding. "Natsu... This guy isn't the run-of-the-mill drone..."
"But we can handle him, Gajeel! We just gotta..." He trailed off, knowing he had no idea how to deal with E.N.D.'s strange magic. "Damn it! I wish I'da read E.N.D. when it was in me, then I could know how to deal with the spells."
Gajeel hit the ground with a heavy thud, dropping into a resting position. "I think I know," he said, staring at the disfigured castle pensively. "When I was lookin' fer Wendy, I decided to brush up on some magic fundamentals, an' I read that every magic that comes from a spellbook can be cancelled if the book is destroyed."
"Destroyed? I can do that."
"Obviously, Mystogun won't be wavin' it around for you to burn. Our best bet is he's still inside that thing, and we're obviously not gonna walk in through the front door."
Natsu glanced at the entrance of the castle, which was dripping with the Dark Magic substance. "Obviously." He watched as the lightning increased, dancing inches away from the roofs of several buildings. "Wait, Gajeel, where are Gray and Wendy?"
"Gray went into the city to rouse the Guilds and warn everyone," he said.
"And Wendy?"
He pointed at the castle. Natsu paled.
"Don't tell me..."
"She thought she'd have a better chance of affecting E.N.D. at its core. I think she wants to make up for not being able to stop Lucy from... Natsu, what the hell are you doing?"
He flapped his wings harder, building up power. "I'm going to save my dragon sister, that's what! Gajeel, you have to stop this-" he gestured at the clouds and Nemesis demons, "-from affecting innocent people. I'm going to end this." He launched himself in the air at his top speed, which was about mach 1, and did the herculean effort of transforming mid-flight. It was quick and more painful than anything else he ever felt in his life, but it further increased his speed by turning him into a living projectile. He saw the wall of goo growing closer and closed his eyes, taking a deep breath. He could almost hear Lucy: You're doing something stupid, Natsu. And he was; before, if he was told he'd be putting his life on the line for humanity, he would've told the person to go to Hell, but now...
You changed me, Lucy, he thought. Time to see if it was for the better.
He collided into the goop bodily, feeling the thud of his impact resonate dully through his bones. He resisted the urge to exhale as he stopped up his nostrils to keep any of the stuff from getting in. (It was something all Fire Magic dragons could do for when they were sick and exuded smoke constantly.) After a while, a curious tickling sensation spread across his skin. The sensation intensified until it felt like little worms were digging into his pores, then it altogether became alarming as the tendrils thickened into ropes that wrapped around his limbs, tugging him deeper into the veil of Black Magic. The last coherent thought he had was, I never got to eat real food, did I?