It's the place where no one can seem to agree on much despite an interconnected history, where the type of food is important and the important people have a lot of influence.
Wait, did I just describe Medieval Europe or Feudal Japan? Or both? Or everything?
Huh, didn't see this one until now:
Character that appeals to South Korea and/or China: One could certainly make the argument that Terry ticks this box too, and that reveal did quite a lot in Chinese social media (KOF 97 was and still is incredibly popular in China, partly due to the ease of piracy. The ease of piracy also helped SNK in LatAm.)
The Steve reveal is probably the biggest there so far (I'd guess 500K Chinese views on the lower end, ca. 1 million on the higher end if my tally is indeed correct). I haven't looked into Korean forums as much - but I found a Korean Youtuber's reaction vid
with 250K views.
As for characters not yet in, I'm going to say LoL or StarCraft. PUBG is a weird spot where it's big in both countries - but the Chinese version is rather different. MapleStory and DFO are still Top 10 games in Korea (and I believe at least DFO has a really strong Chinese playerbase), so they're valid options too. One could also argue Overwatch and Reimu. Really, the list is surprisingly long, but I'll go with LoL first.
Character that appeals to a female audience: This one is also surprisingly vast. I'm going to use
this 2017 study as the baseline of my answer:
Arle is a strong choice because the Match-3 playerbase is largely female (and this would likely translate to Puyo Puyo). Wouldn't be surprised if characters like Reimu likewise have a decently strong case here. The Sims series is likewise played by a lot of girls / women. When it comes to spirited series, Ring Fit has a rather strong followings amongst girls and women too. Assassin's Creed and Dragon Age have rather strong female playerbases too, especially relative to their genres. I wouldn't be surprised if Resident Evil also has a strong following amongst girls and women, although I haven't found a direct source for that. Girls and women form a very strong part of the mobile audience - Candy Crush Saga is a major example. So a mobile rep could also in many cases be targeted towards women.
I'm going with Arle first.