OOC || PERMISSIONS
Negative Triggers || Insults/Threats toward friends, Illumi, Loss in general, Betrayal, Spiders and Ants
Positive Triggers || Competition, Challenges, Gon, Chocolate
Unwanted Physical Contact || Perfectly fine, just prepare to be seen as a cootie monster. Or compared to Hisoka. Or, well, be Hisoka.
Relationships || Unlikely, but with enough CR and a good spark under their belts, it's possible. Get ready for a lot of awkward adorableness and petty arguments.
Injury || Contact me. Most likely a big yes.
Torture || Contact me. Most likely a biiiig yes. Killua is capable of enduring some very disturbing and painful torture methods and still talking back like nothing's wrong.
Death || Nope.
Mind Effery || Contact me. Killua is pretty darn susceptable to this. Too much could break him.
Fourth-Walling || Absolutely no mention of canon past what he knows (Chapter 294). Let's not traumatize him with Gon!Hulk, pretty please.
Threadjacking/Hopping || Why would anyone say no to this?
Hacking || Go for it if your character is capable. But Killua's a fast learner.