The GrUvia Mission

Part 1: Strategy

"Gray, I'm assigning you on a mission with Juvia," Erza handed him a piece of paper from the quest board. It was a sunny afternoon. Everyone was having fun at the guild. Lucy was with Juvia, trying out her tea. Natsu was having a brawl with Gajeel. Mirajane was busy serving drinks.

"Why Juvia?" He looked at the contents. ""Fire Demon Causing Chaos In A Forest"? So you're saying its weak against ice and water? Why can't I go myself?" He leaned against the quest board. Gray wasn't very keen to go on a quest with Juvia. Her love obsession was too distracting.

Erza stared at the paper for a moment. "The fire demon is stronger than you think. It's not to be underestimated. Juvia's water will prove very useful too, and you two will make a good team against it."

Gray recalled the unison raid he did 7 years ago with Juvia when Natsu was trapped in the artificial dragon. He blushed at the thought of not noticing her feelings earlier. Thinking about doing it again made him feel more reluctant to do the quest.
"Why can't you go instead?" he grumbled.
"I have another quest to complete. Why are you so reluctant to go with her?" she crossed her arms.
"Its not like I hate her or anything...It's just..." his voice trailed off.
"Just go. Maybe you can make things clear with her along the way."
"Fine," he scowled.

"Juvia is going on a date with Gray sama!! How lovely!!" She blushed hard as she shook her head left and right with her hands on her cheeks. "It's not a date!!" he blushed. They were walking in the forest stated in the quest. The forest looked fine, but the air was very warm, and there was no sign of fire demon anywhere.

"Is this some kind of joke?" The ice mage took off his shirt. "If it is, its seriously not funny," he looked around. The air felt wrong.
"It's...it's so hot...It's getting hotter. Juvia has never felt this hot before..." she breathed heavily. Juvia was sweating head to toe. Gray noticed he was sweating too. The heat was so intense.

"Hold on, I'll cool you down," he reached for Juvia's hands, but before he could reach it he felt his magic power drained to its limit. He fell on his knees in an instant. "Gray sama!!" Juvia gasped. His vision was blurry. Juvia's voice was like water. What was happening to him? Why can't he move? He tried to get up but the gravity was forcing him down.
"Kya!!!"

Gray's eyes widened. The fire demon was right in front of him, grabbing Juvia's neck. It looked revolting. The face was distorted, but the body was human-shaped. Juvia struggled to breath.
"Water Lock!!!"
She drenched the demon in a blob of water. The water turned to steam in an instant. "Impossible!!" she cried.

Gray felt a surge of power enter him. He was regaining strength. It seemed the fire demon could only focus at one target at a time. He got up immediately and grabbed it from behind. The burning heat was so intense that he could feel his skin burning into his bones. He forced to resist and wasted no time before the demon could drain his powers again.
"Ice Make Statue!!!"

The demon was finally frozen stone. A few seconds later, it started to melt. Gray wasn't surprised, considering how intense the heat was, but at least they had enough time to retreat for now. "Let's go, Juvia!"
"Yes," Juvia coughed for air after he pulled her out of the demon's clutches.

"I think we're safe over here, for now," They stopped at a cave after running for hours non stop. They needed to think of a better plan and recover their magic powers before attacking the demon again.
"What if it finds us?" Juvia wondered aimlessly in the cave, dragging her fingers on the walls slowly, she looked at him.
Gray blushed. He suddenly remembered that he was alone with Juvia.
"Let's just hope not. Besides, we've run so far," he tried to look at the bright side, but he still didn't know what its weakness was. "That amount of heat...it was worse than Natsu's," he hinted.
"How is that possible?" she whispered.
"I don't know. Natsu's really strong. That demon must have had his own way to intensify his heat..." his voice trailed off, then his eyes widened. "Damn it!! I should have realized sooner!!" he cursed.
"What is it?"
"That thing, it has the power to control temperature!!" he confirmed.
"But how did he drain Gray sama's magic power?"
Gray paused for a moment. She's right. How did that happen?
"Maybe...maybe it wasn't draining my magic. It must have increased my body temperature drastically," he wondered.
"B-body temperature..." she blushed

"A-anyways, we should get some rest. How's your neck? he sat down.
"It still hurts a bit but Juvia will be fine," she smiled nonchalantly and continued. "Maybe Juvia should stay up to keep watch--"
"Oh, right," He got up and froze the entrance. "It won't sense our body heat now. Well, just in case," He looked at Juvia.
"B-b-b-body heat??" she squealed.
"I-I-It's not like that!!!" he blushed hard.