hi! try these:
http://www.mangago.me/home/mangalist/846297/
http://www.mangago.me/read-manga/brutal_satsujin_kansatsukan_no_kokuhaku/
http://www.mangago.me/read-manga/the_hero_who_seeks_revenge_shall_exterminate_with_darkness/
http://www.mangago.me/read-manga/bastard_hwang_youngchan/?WNwI
http://www.mangago.me/read-manga/the_breaker/?cbmf
http://www.mangago.me/read-manga/ajin/
http://www.mangago.me/read-manga/ranker_who_lives_a_second_time/
http://www.mangago.me/read-manga/nidome_no_yuusha/
http://www.mangago.me/read-manga/prison_lab/
http://www.mangago.me/read-manga/rooftop_sword_master/
http://www.mangago.me/read-manga/the_villainess_reverses_the_hourglass/
http://www.mangago.me/read-manga/shadow_queen/
http://www.mangago.me/read-manga/legend_of_the_northern_blade/
http://www.mangago.me/read-manga/resurrection_of_the_catastrophic_hero/
http://www.mangago.me/read-manga/juujika_no_rokunin/
http://www.mangago.me/read-manga/the_villainess_lives_twice/?oWwp
http://www.mangago.me/read-manga/the_holy_grail_of_eris/
http://www.mangago.me/read-manga/i_want_to_be_you_just_for_a_day/
http://www.mangago.me/read-manga/skip_beat/
http://www.mangago.me/read-manga/beware_of_the_villainess/
http://www.mangago.me/read-manga/the_villainess_slow_prison_life_began_with_her_broken_engagement/
THANKS!! (づ￣ ³￣)づ
I'm looking for mangas or webtoons with a delicious revenge plot, please help meee