Anti Hero ML / Real bad guys / criminals

SML (practically equally ML) is almost villain

ML is anti hero / gangster

ML is anti hero / contract killer

SML (practically equally ML) is villain

SML is anti hero/almost villain (real villain's son)

(it's long drama and SML has more then enough his own story, romance (which is best part of this drama) and everything for full drama with him as only ML)

ML isn't typical good, he makes unusual choices

SML is  villain/serial killer

from 3 main male leads one is real anti hero/villain (though this drama isn't simple with one and strictly defined villain) and second is very multilayered character, you can't say is he good guy or bad, at list he becomes worst, he doesn't want but situations make him choose path which is cruel and he didn't wanted to become cruel....
also from 2 main female leads one is anti hero/questionable morality

*** drama has 3 parts, I just tagged third because anti hero/villain vibes are more strong here

SML (practically equally ML) is almost villain but also star of the show

ML is anti hero

ML is anti hero / dark-mysterious guy 

Japanese original of "Smile has left your eyes" and more dark

ML is anti hero / dark-mysterious guy

ML is anti hero, good guy ho becomes quite bad person trough his revenge on FL

ML is anti hero who becomes practically villain

SML (practically  ML, both of them are main characters) is anti hero (son of villain)

real SML type character (very interesting/charismatic) is more anti hero

main leads are criminals / anti heroes

ML is anti hero who never changed into "good person"

ML is anti hero  (there are 2 lives/reincarnations, in one he is more "bad")

ML is con man/anti hero

bad for FL, not in general criminal or something 

anti hero ML (at list first part of drama)

ML - bad moral choices, 

SML - real (d)evil :))

SML is anti hero (he isn't almost ML like in previous dramas here, but quite main especially with one aspect in the end)

ML and SML and most of the characters are anti heroes (supernatural creatures) tough drama is light, often funny and not dark

ML is anti hero (quite dark/cold/ruthless grim riper though humanized through the show. though drama is about dark supernatural creatures, overall isn't dark, just like "Korean Odyssey")

FL is unredeemable villain

FL is classic anti hero, also most of the characters are gray (not good not fully bad, some more anti heroes)