You have to swear yourself to me

This is basically what you guys requested! I'm a little sad I couldn't create my idea, but if it'll make you guys happy, then.... Read away!
For those who don't know about the little poll I held in "school days" where I asked if you guys wanted yandere killua, yandere gon or yandere both; and of course yandere killua won :'), oh well, I'll do the best I can! So enjoy this yandere killua x gon book! ^^, please?