highly recommend this if you're okay with murim stuff
https://www.mangago.me/read-manga/myst_might_mayhem/
the mc is pretty deranged and actually evil so you're reading from a villain pov. it's so interestingლ(´ڡ`ლ)
https://www.mangago.me/read-manga/surviving_as_a_genius_on_borrowed_time/ - actual genius martial artist MC who has bad constitution that might kill him
https://www.mangago.me/read-manga/superhuman_battlefield/ - super powered humans that are pro athletes is the summary in my head. Completed work
https://www.mangago.me/read-manga/the_magic_tower_s_problem_child/ - mage saves the world and comes back in the body of a troublemaker 20 years later (i think it was 20. Need to confirm that)
https://www.mangago.me/read-manga/the_return_of_the_8th_class_magician/ - haven't actually read it (tho in my reading list for a long time now) yet but it's got high rating plus it's completed.
https://www.mangago.me/read-manga/heavenly_grand_archive_s_young_master/ - chaotic hilarity juxtaposed with merciless, bloody retribution. Murim alliance leader gets killed and immediately wakes up in a body of a suicidal dude. Interesting start and just a mess of laughter and damn good violence. You understand why he was Murim alliance leader in his previous life.
any good action/fantasy manhwa with male mc and consistent characters/story?