does anyone know the name of that one action manhwa where the mc has red hair and when he ...

Action with no romance -
https://www.mangago.zone/read-manga/trash_of_the_count_s_family/
https://www.mangago.zone/read-manga/the_newbie_is_too_strong/
https://www.mangago.zone/read-manga/return_of_the_flowery_mountain_sect/
https://www.mangago.zone/read-manga/chronicles_of_the_martial_god_s_return/
https://www.mangago.zone/read-manga/academy_s_genius_swordmaster/ no romance so far
https://www.mangago.zone/read-manga/the_terminally_ill_young_master_of_the_baek_clan/ so far
https://www.mangago.zone/read-manga/living_as_the_enemy_prince_sellascans/
https://www.mangago.zone/read-manga/academy_s_undercover_professor/ not sure if there is in the novel
https://www.mangago.zone/read-manga/one_hit_teacher_master_baek/
https://www.mangago.zone/read-manga/the_return_of_the_crazy_demon/
https://www.mangago.zone/read-manga/life_of_a_magic_academy_mage/
https://www.mangago.zone/read-manga/how_to_live_as_a_bootleg_healer/
https://www.mangago.zone/read-manga/how_to_live_as_a_villain/
https://www.mangago.zone/read-manga/hero_killer_1/
https://www.mangago.zone/read-manga/margrave_s_bastard_son_was_the_emperor/ so far
I'm not 100% sure, but none so far(at least according to my memorie)

omg tysm