Beginning: the Steel Bar Penetrates the Abdomen, You Say It's the Commander?

[Apocalyptic wasteland + system + decisive killing + civilization reconstruction] All my teammates were wiped out, and a steel bar penetrated my abdomen. I was lying in the rubble, waiting to die from blood loss. As I lay dying, the cold system sounded in my mind - [Supreme Order: Restore Civilized Order]. But the task of activating it is to ask me, a dying person, to save others first? Looking at the longing eyes of the survivors not far away, I looked at the bottle of life-saving water in my hand, which was more precious than gold, and thought of my fallen comrades and my oath as a soldier. I didn't drink this bottle of water, so I threw it out with my last strength! "Mission completed, permission activated!" "Reward distribution: Emergency survival kit × 1!" However, before I could take a breath, a piercing alarm sounded in my mind: [Warning! Multiple high-threat aberrations are approaching at high speed! Arrival time: 90 seconds! I, Chen Xing, am a useless person who has just crawled back from hell. In front of him were three unarmed survivors. In the distance, there is the bloodthirsty monster that is coming. And my system is the "Doomsday Commander System". From a dying soldier to the supreme commander in charge of the fire of human civilization! Scan resources, unlock black technology, expand the shelter, and arm the survivor army! The brothers' revenge must be avenged! The world shrouded in gray fog will be purified by my own hands! I have the final say on the order of this wasteland!