The kiss

Lucien was left puzzled.

What makes you so certain? Lucien was bombarded with a strong sense of guilt.

The little protagonist raised his head. His crimson eyes were dark and deep. His pupils reflected Lucien's confused face.

It doesn't matter if he was confused. As long as he found him. He won't let him escape.

Aiden's eyes flash, and the innocent crying face he put on earlier disappeared. He no longer cried and wailed in Lucien's arms. Instead, he tightened his hold around Lucien's arms. 

Above his head, Lucien witnessed the system's prompt change again. From, 

[Fight the serial killer and save everyone from being murdered.] into,

[Kill the mass murderer.]

Intense goosebumps force Lucien to shiver. He immediately shove Aiden away and decided he'd rather fail this instance game than to kill the little protagonist with his own hands.