Heresy. Well it's not rly badass, but truly quality. (Almost no action)
https://mangadex.org/title/34771/heresy
Dark Lady it rly is slow, but good, though (also not that much action)
https://mangadex.org/title/39012/mookhyang-dark-lady
Reverse villain that is badass
https://mangadex.org/title/44575/reverse-villain
https://mangadex.org/title/1206/shin-angyo-onshi
(https://mangadex.org/title/15553/tensei-shitara-slime-datta-ken)
Ruler of the land has a really slow start, but becomes at the end truly badass. This thing is so old that the main character changes tremendously.
https://mangadex.org/title/660/the-ruler-of-the-land
https://mangadex.org/title/14740/xian-ni