OK, I thought I'd revive this thread because, while looking over the RAWs of the manga, I realised that, in Japanese, Crimson Riot and Fourth Kind respectively have different Hero epithets that can both be translated as "chivalrous".

Crimson Riot uses the kanji "漢気", which is "Kan ki", while Fourth Kind uses the kanji "任侠", which is "Ninkyou". So the kanji involved in each of their respective epiphets is different, but, given that I'm not, like, a fluent Japanese speaker who knows all the nuances or anything, I don't know how you'd be able to adapt their titles in English so they're different to each other. Does anyone who does know Japanese have an idea?