"I'm not liking this" Zenitsu said nervously, hiding behind Tanjiro. They were standing right outside Killua's cave, and Zenitsu was chickening out. Gon sighed. "Zenitsu. If I don't introduce him to you properly, then your actually in more danger" His eyes widened, Tanjiro was just standing there patiently. "H-How?" Gon laughed. "If he comes across you while I'm not there and he doesn't know your my friend, he'll eat you. I've managed to establish boundaries about eating certain people, but not all of them." He turned his back, then shouted into the cave. "Killua! I want you to meet someone!" There was silence for a few moments, then Killua emerged with his tail flicking slowly over the ground. Zenitsu ducked behind Tanjiro, but Gon gave him a look and he gulped.

Tanjiro removed himself from Zenitsu, grabbing his shoulders and making him stand in front. Poor Zenitsu looks terrified. "Yes?" Gon grabbed Killua's arm, then pointed to Zenitsu. "He's off limits too. His name's Zenitsu" His ears flicked, and he dipped his head. "Understood" Zenitsu blinked, then seemed less scared. "Oh...He doesn't seem very...evil." Gon shot him a look. "Because he isn't." Zenitsu threw his hands in the air. "I only saw him once, briefly, and he was devouring a human." Suddenly Killua's tail stilled, and he looked out into the woods. Gon activated En, and his eyes sparkled when he realized it was a demon. Perfect opportunity! "What is it? You just got excited" Tanjiro asked, curiously following his eyes. The demon wasn't very close, but it was heading their way. Killua took a step, then paused. Gon grinned at him. "Go for it"

He bolted towards the demon, and both the older demon slayers jumped. "What's he doing?" Gon giggled, then ran after him. "C'mon!" He was really curious about what Killua would do, he had two theories. Suddenly there was a scream, and the other two ran faster to catch up with him. "What-" They emerged into a group of trees, and the other two froze. Killua had the demon restrained on the ground, and was currently sucking the blood out of a deep gash in her neck. "YOUR NOT SUPPOSED TO KILL THE PEOPLE ON YOUR OWN SIDE!" The female demon screamed, struggling with terror. Killua's tail slid up to her mouth to silence her, then his ears flicked and he kept feeding. He needs blood to live. With the way he thinks, he'll try to find it the quickest and most efficient way possible. Gon thought, a small smile on his face. I can work with this.

"H-He's...feeding from his own kind" Zenitsu said faintly, still in shock. Gon leaned on a tree with that small smile still on his face. "He doesn't care how he gets the blood, as long as he does. Killua doesn't think about what's ethical and what's not, he thinks about the quickest and most efficient way to do something. Well, at least in this state" Tanjiro hummed in contemplation, then murmured. "Muzan's blood is in every demon, he uses it as a reward system for doing things like killing hashira. If they get the job done, he gives them some of his blood" Gon got an idea. I think...I think I just solved the problem. Well, the first one.

They watched as Killua kept feeding, then the demon disintegrated. He licked the blood off his hands and tail, then went back over to them. Gon smiled. "Killua, did you know that demons have more of Muzan's blood in them than humans do?" He blinked at Gon for a moment. "They have...more? Thought it was...same. Unless one of the 12" Gon shook his head. "Humans don't have any at all actually. Sure it's blood, but not his." Tanjiro's eyes widened slightly, realizing what he was trying to do. Killua hummed for a moment, tail flicking back and forth. "Humans...more of them. 15 a night usually. Can't find that many demons in one night" Gon winced slightly. "3 slayers a week..." He said, and Gon paused. "What was that?"

Killua flicked his tail at Zenitsu, causing him to take a step back. "50 demon slayers or 1 hashira and I get some blood. 3 a week, should take 4 months. Less than 6, better than my last goal." All three were shocked for a moment, and Gon rubbed the back of his head. "How...how far along are you on this goal?" He asked, kind of nervously. Killua's ears flicked. "5, started not that long ago" Ah damn, this might be an issue. I can't just let him free feed with that kind of goal in his head. "You don't need Muzan to give you blood if you can just get it yourself" He said, smiling. Killua's tail flicked in contemplation, so Gon beamed. "I could teach you some techniques" Killua's ears perked up a bit. "Like...what?" He thought for a moment, then pointed to his eyes. "You can extend your senses outwards yes?" He dipped his head, and Gon smiled. "Instead of extending outwards, do it in your eyes. That's called Gyo"

He saw Killua's eyes narrow slightly, then he blinked in surprise. Gon held a finger up and his lips parted slightly. "Number...2. How are you doing that?" He grabbed Killua's hand. "C'mon! I can show you!" He said, then leapt upwards into a tree. Killua leapt beside him as they went from tree to tree. "Where are we going?" Killua said. He giggled and then dropped down when they came across a stream. "I'm gonna teach you something! But first, I have a question" He slid down the tree, then nodded. "Ok" Gon bit his lip. "Do you...have any memories? At all? Do you remember anything?" Killua's tail flicked, then he slid a hand into his pocket. Gon's eyes widened when he pulled out an exact replica of his old knife, but instead made of stone. "This...knife." Gon reached into his backpack and grabbed out both knives, his and Killua's. "Here, it's yours" He said, handing Killua the weapon.

He took it, then spun it around a bit. "Mmm..." Gon smiled, then showed his own. "you...gave me an identical one. For self defense, you always got so snippy when I didn't carry it around with me" He said, kind of sadly. Killua's tail flicked, and he did a few slashes. Gon noticed how they weren't as refined and skillful as they used to be, so he smiled. "Want to...spar again?" Killua blinked. "Why?" Gon beamed, spinning his knife. "it helps you get stronger, better at combat. You're not that great with your knife anymore so we could work on that alone" Killua blinked, then darted forward with a slash. Gon dodged, countering and spinning his knife into reverse grip. Killua taught me all about knife to knife combat, I should be able to teach him some too.

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To be continued...