Evilive

Han Dong Soo is a livelihood lawyer. He randomly picks a prisoner to visit and picks up a case. He is usually rational and reasonable, but deep within his mind exists a dark side. Something triggers him to cross the line and step into the world of evil. His younger half-brother is Han Beom Jae. Han Beom Jae works at a second-hand computer shop and he also acts as a case broker for Han Dong-soo, bringing him clients. One day, Han Beom Jae notices that Han Dong Soo has changed since he brought him a case.
That case involves Seo Do Young
who is the #2 ranked member of a crime organization. He is a former baseball player and appears nothing like a typical gangster. Behind his handsome looks, he hides a cruel and unpredictable madness.
(Source: Asianwiki)