In Parasyte: The Grey, Detective Kang Won-seok is a colleague of Chun-mil and the only human being voluntarily working for the parasites. Kim In-kwon plays Won-seok.
In the series, Detective Kang Won-seok is facing a life full of struggles. With the salary that he gets as a cop, he doesn’t think he will be able to provide for his daughter.
Hence, Won-seok is constantly seen seeking a promotion or an opportunity that will earn him and his family a better living.
This dire need for a better life leads Won-seok to start working for the parasites, who promise to make his dream come true.
The deal
Won-seok meets a parasite for the first time when he drops by the house of a pastor from the church he goes to.
The pastor, Pastor Kwon, had killed his wife, as a parasite had parasitized him. Before Won-seok can arrest Pastor Kwon, the parasite shows its true form.
The parasite in Pastor Kwon’s body doesn’t kill Won-seok. After studying how humans operate, he intends to have Won-seok join them as an ally.
The parasite promises that Won-seok will also have to gain, and if Won-seok rejects this offer, he will die. Won-seok ends up accepting the deal.
Won-seok’s fate
Throughout the series, Won-seok assists the parasites, betraying his people. He is responsible for the deaths of the Hunting Dog and Chul-min.
Won-seok aimed to fill in a top position once the leader of parasites switched to the body of Namcheon’s mayor.
However, in a desperate move to survive, the parasite killed Won-seok to take over his body and hunt the mayor down before being defeated by Heidi and Jun-kyung.
Also Read: Kim Chul-min’s death in Parasyte: The Grey explained