I read/watched the series, manga and anime, all the way through, so I know the character is OP and because of it, it's extremely difficult to play them in a game. I've played a few characters that were OP and I know it's difficult to remain IC with a character that just wants to fight all the time b/c the urge to curb their personality to something easier to digest is strong. So, I applaud you for keeping his personality intact. Just because he has no memories doesn't mean his entire personality changes. Same goes for his abilities. Simply because he's a shinki doesn't mean he's a wimp or suddenly not an OP character. His entire character revolves around being OP. It's kind of why he was made in the first place. He's the guy they drop in when there's a bad guy they need to take down that isn't the main baddy b/c that one Tsuna has to take care of once he finally believes in himself.

Like I said, he's a difficult character to play in general b/c he's naturally going to be on a lot of people's bad side due to his personality and, let's be real, he starts fights over anything. Sometimes, characters like these just don't work well in games bc they tend to clash with almost everyone they meet except for those one or two people they miraculously can somehow stand. Hence why I thought the only advice I could give here is to make an Opt-Out post for him and spread it around the OOC community, but I noticed you already have an Opt-Out Post for him in the HMD on his journal, so I guess my only 'real' advice is to remind people every few months. He's a new character this round so I still don't have a good feel for him, since we've only interacted in on thread, but so far, he seems pretty IC, so keep up the good work!