After an hour of hiding, you decided that that was enough fun for that day. You stopped hiding your presence and Killua was quick to come to you. "Your brother is weird." You said when he finally caught up to you. "Which one?" "Isn't his name Illumi or something? The one with the long hair." Killua rolled his eyes, "Yeah. But everyones weird here. Now, can we start?"

Timeskip

You tossed Killua a water bottle, "That's enough for today. You did well." He scoffed, "But I didn't even do anything." "True but you got close. You've almost figured it out." "Really?" You nodded. You saw him smile to himself. In truth, what he was trying to learn was a combination of several things he already knows. It took a few months for you to come up with and master it. At first you got the opponent to look away from you. After training, you managed to get your split time to less than a second. The second you wasn't quite a clone. Close but not quite. It was like another more watered down version of yourself. You learned that by taking more from yourself and channeling it into the second you, the split became stronger though it left the real you more vulnerable. The lack of life energy, however, made it easy for you to make yourself invisible. You quickly realized that it wouldn't always be possible to get the opponent to look away from you so you had to both split, transfer the energy, and conceal yourself all at once seamlessly. Once you got the hang of it splitting became second nature so it was rather difficult to explain it. Killua was smart though. "I'll be right back. Ganna go get a snack. I'll grab you something." said Killua before running off towards the house. "So it's a clone. That's easy." You swung at the sudden voice behind you out of surprise but your fist was caught. Your kick, however, wasn't. You stood over Illumi who didn't seem in much of a hurry to get up. He stared up at you blankly. "It's not a clone. Not quite." He looked confused, "Then what is it?" You smirked, "That's for you to figure out. Killua is getting close but hasn't yet. I'll guide you in the right direction but you have to figure out the specifics." He sighed, "How am I supposed to figure it out if i've never seen it before?" he asked in a deadpan. "But you just did." You said reaching down a hand and pulled him up. He didn't let go of your hand. He pulled it closer to his face and looked at it, squeezing it. "You don't seem to have changed." "I didn't change. I just split." You said from behind him. He whirled around with the other you's hand still in his. "I thought you said that this wasn't a clone." "It's not." "But how?" He was beginning to sound frustrated at his lack of understanding. 'A little bit of payback.' you thought smugly. You shrugged, "You tell me." He narrowed his eyes, "Do it again." The second you dissipated. You saw that he noticed the shifting of energy. You stood in front of him. You also stood behind him. "You didn't do anything. Tell me h-" "Aren't you a top notch assassin? You should be able to figure this out." You said from behind him. He huffed, "I can figure it out." You rolled your eyes from in front of him, "let me know when you do that. I'm gonna find Killua."

Timeskip

Killua had figured it out for the most part. He still wasn't 100% on the shift in energy but he was getting there. Illumi invited himself into the training sessions you had with Killua making him your slightly unwilling teacher. You laid on the ground as you waited for Killua to return. He always insisted on taking snack breaks. You were once again alone with Illumi. You sighed as he walked towards you. "I think I've figured it out. At least a part." You raised an eyebrow, "Really? Show me then." "I did." He said smugly. You rolled your eyes, "You're behind me right now. Your split is standing in front. You didn't transfer the energy." He scoffed and crossed his arms. You had to admit, that was adorable. You chuckled, "You'll get it eventually." You got up from the ground. "Spar with me." He said. "Why should I?" You asked. He suddenly turned around, pinning your split that was creeping up behind him to the wall. "Nice t-" "Got you." You said with a smile. You held one of the daggers that were on the wall to his throat. "That's not fair. Another match." he demanded. "You sound like a sore loser." You said, tossing the dagger to him and walking away. You felt two arms snake around your waist. He didn't throw you like you thought he would. He just picked you up enough to let your feet dangle. "Put me down." You said trying to struggle out of his grip. "Tell me how to do that thing you do then." "No." You said stubbornly. He suddenly flipped you over in his grip, still not letting your feet touch the ground. You put your hands on his shoulders to get your face farther from his. You tried to ignore the feeling of his body against yours while you tried to get out. He cocked his head to the side, "Are you the real one or a split?" You crossed your arms, "Not telling." He began walking. Toward what you couldn't tell but you wanted out. "Put me down idiot." You demanded. "If you're a split, you can just dissipate. You might just be being stubborn right now." You felt your back against a wall. "It's difficult to tell the difference between the real thing and a split." He leaned closer, "If I can determine whether or not you're a split, I might be able to do so in the future." You could have leaned back further but you didn't for some reason. "Let me down." You said ignoring the heat in your cheeks. He leaned in closer. At this point your noses were touching. "So. Are you real or a split?" Still as stubborn as ever, you said, "Not telling." He leaned in closer, centimeters away from you. His arms sid from your upper back from where he initially grabbed you to your lower back. He pushed you harder against the wall and you wrapped your legs around his waist, having no other choice. "Real-" his lips were almost touching yours, "or-" his lips ghosted yours as he spoke, "split?" "not telling." You whispered. You surprised yourself by closing the gap. Your head almost hit the wall as he reciprocated the kiss. Your arms wrapped around his shoulders. You were also the one to pull away first as he could go without breathing for who knows how long. "Interesting. Guess you weren't a split."

(bonus scene)

Killua sat on one of the benches outside of the training ground, looking traumatized (which is saying something coming from him) His snacks were left abandoned as his appetite was gone. (Once again, a big thing is coming from him.) He shivered as he remembered what he had seen. 'He really couldn't have closed his eyes?'

I had some free time so I went ahead and finished it. Requests are open so please leave yours in the comments below. As there are no further requests as of now I'll have to skip the part where I list them. Anyways, I hope you enjoyed and see you in the next chapter! So YEET.