C913 Kill or not kill
The reason why Chen Fei did not help Ma Dongmei was because he did not understand the situation. Instead, he had full confidence in Ma Dongmei.
Ma Dongmei was the Blood King, and had always been Chen Fei's trump card in all previous instance dungeons.
Even when facing the soldiers of the Level 7 Player, Ma Dongmei had never lost.
Furthermore