Responses
A few that come to mind are:
Blood Poker « Green flag top that barely talks + guideverse
Kiss Me If You Can « Gloomy/Bratty top (at first) + omegaverse
Futariyogari na Melty Charm « Quiet seme + magical/Hogwarts type school setting
he's very kuudere, but he does blush and pout in a sad gloomy way.. very kawaii:
https://www.mangago.me/read-manga/sugar_trap/
BL recommendations: ABOUT a gloomy, barley reacts to anything or barley talk kind of TOP/Seme ლ(´ڡ`ლ)