1). Backtagging: Always and forever <3
2). Threadjacking: Unless it's encrypted, feel 110% free to hop in! I really like threadjacking...
4). Fourthwalling: Sure.
5). Offensive subjects: Go on, it's fine with me.
1). Hugging this character: Yes. He will :| and shove them away, most likely.
2). Kissing this character: Yes. He will either do the above, or use too much tongue.
3). Flirting with this character: Yes. It might well go over his head... orrrr he might try to sleep with them.
4). Fighting with this character: Yes please! Though he'll hardly ever throw the first punch, and see the note at the end about goofy Nation powers*. Verbal sparring and immature name-calling are also fun and he will totally throw the first insult.
5). Injuring this character: As long as he keeps his limbs and doesn't die it's whateveh. He's not a wimp himself though, expect some retaliation.*
6). Killing this character: No.
7). Using telepathy/mind reading abilities on this character: Yeah, just shoot me a line first, I can help you out there.
Warnings/FYI?: *As a Nation he's a lot stronger than your average human, though even at "human strength" he's pretty darn fit. Like Himaruya brings up how muscular he is about four different times. However, headcanon is that it's super taboo for Nations to attack citizens - so if he thinks your character is a standard (human) citizen from Earth, there's basically no way he would use that freaky strength against them. Normal-people punches are a go!