The only things in combat Yun-chan excels at are range and accuracy. Her defense and HP are low that she will die in 2-3 hits from monsters of the same level as her. Her damage output is sub-par. Her reaction time is also sub-par.
@Edjan:
1st: My guess is, they either didn't want to wait or weren't sure if they make it to a match, in which they would face each other. Or maybe they didn't want to kick the other out after they came quite far. (No hard feelings approach.)
2nd: At first I thought the exact same thing as BloodySorcerer, but you are right.OSO ch.45 p.30. My guess, why hey said he allows it, is, that it's because he's a know PK or because he attacked his friend. Or maybe because nobody else joined the fray after it started and he was pretty late also, as a reminder and it might have been badly translated. "This is allowed, but there is a penalty" instead of "I allow it, but..." Yet again, just guessing.
3th: "Normies must die" isn't logical. It is absolute!
4th: Not changing the rules of the game, but outlawing it by creating PK hunting events or Quests sounds good.
5th: The system auto-recognition falsely registered him as female. So, if it is listed in his states, it's wrong there. And him telling everyone, he isn't a girl, might be just interpreted as a girl's strategy to ward of annoying gigolos. Also his sister's don't help at all.
2nd: Flein was an "intruder" and got his stats cut not because he's a PKer, but because he jumped in late (when other players were already beaten/exhausted). "Anyone is free to jump into the fray if they wish, no registration necessary. Though a penalty will be applied each time you enter."
And the "I'll allow it" bit was more Claude acting as the Great Tournament Overseer-type. Roleplaying, basically.
And my two cents about all the PK stuff: The game seems focused on letting people play it however they want. Whether that's being a Monster Hunter, Crafter, Farmer, Shady Merchant, or even a PKer.
@Edjan
Basically to clarify Yun is female in game. The manga skips out or hasn't gotten to the parts that confirm this. Despite Yun telling everyone they are a man, it's impossible to play as the opposite gender that you are IRL. Yun was black mailed by Sei to remain playing as female (she threatened to release Yun's dark history) and the game classified Yun as female and made his body to match so in "her" status it shows female.
1)Only 4 people know Yun is male IRL.
Myuu and Sei - Yun's sisters who treat Yun as a fellow sister instead of as a brother both IRL and in-game. Myuu will calls Yun Onee-chan (sister) outside of game a couple of times instead of Onii-chan (brother), it's not clear if this is an accident or on purpose. Both Sei and Myuu refer to the 3 as sisters both IRL and in game so take that as you will.
Taku - Yuns Best Friend IRL - Who treats Yun as a girl In-game and seems to not want to tell everyone Yun is male IRL (it's alluded that there is a reason for this but thats spoilers).
Emily - Yun's IRL classmate - She knows Yun is male IRL, but thinks Yun is trans or wants to be a girl. A few scenes are skipped in the manga with her and Yun going shopping for cake IRL and also the scene where they meet in game is mostly skipped over , she also thinks Yun is in love with Taku. This is why she doesn't tell anyone Yun is male IRL.
From the LN, Not a spoiler as this scene has already happened in manga but was completely skipped. This is the scene where they meet in-game for the first time. This is the dialouge that was left out.
Emily :『"You're completely different than you are at school and do things are your own pace, don't you."』
Yun: "Mm? Is that so?"
Emily: 『"Well, that's because you're living a life there conforming to rules... so it doesn't stand out, but you're quite free here aren't you."』
then
Emily: 『"Also... you've had a desire to transform yourself after all."』
Yun: "I didn't! This is a bug! Character edit's body correction misidentification! Heck, what's up with 'after all'! C'mon, what is it?!"
When I grandly retorted in inaudible voice in the middle of the empty forest, from the other side of the friend call I've heard a strange, quiet laughter.
Emily: 『"I didn't think you would deny that strongly. Still, it suits you."』
then the icing on the cake
Yun: "There's something I'd like to ask... is the reason why you stare at Taku, explore how to talk to him and know about videos with him because——you like Taku?"
Emily: 『"Haa?! No such thing! Absolutely not."』
Yun: "E-eh?"
Even though she inquired so meaningfully earlier... so it was my misunderstanding.
Emily: 『"The reason I was bothered is because I didn't want to meet him. It'll be troublesome if I'm found out to be a player right? It has nothing to do with love!"』
After hearing Emily-san deny strongly, I let out a sigh of relief.
Yun: "Is that so."
I muttered and it turned silence. Afterwards, I spoke from my side again.
Yun: "Um, let's end this topic. For some reason it feels like I'm bringing trouble on myself."
Emily: 『"You're right. I won't touch the subject of Yun-kun being of different sex in OSO in relation to Taku-kun."』
Both of us were convinced, "let's change the topic" said Emily-san.
2) In later parts of the story it is confirmed Yun is female in game.
Non Story related spoilers
In Vol 8 there is a hotspring scene. The game won't allow Yun into the male side and is forced into the female side. Then after they enter Yun is teased by Sei and Mikadzuchi about their bust size. There is also a beach section with Yun in a swimsuit.