Gao Yang's heart was uneasy, worried for the Osa he had tied up, and also for Number Thirteen, especially when Number Thirteen's eyes lit up upon seeing Osa, he truly began to feel terrified.
As a mercenary, slaughtering enemies on the battlefield is surely different from watching a pervert kill the person who brought him here, right?
If Number Thirteen had taken extensive precautions to prevent that woman from possibly leaking secrets after being questioned, Gao Yang would have accepted it. But Number Thirteen specifically had Gao Yang drive Osa directly to their base, the longest-standing base where Satan had always lived.
Number Thirteen dared to do this, feeling confident and fearless, but Gao Yang felt that aside from killing Osa, it seemed there was no other way to seal her mouth. Either keep her locked up or kill her, because it would be strange if Osa didn't report to the police once they let her go.