I Bring Tech to Crush Magic

Chen Yifan survived the end of the world before he was pulled into the cultivation realm, and Liu Yanyan saved him there because his Pure Yang body made him worth hunting. Neither of them trusts the other at first. They form an alliance anyway, and it becomes something closer while both of them are still calculating. Ji Fu and Wang Sen move against the palace in a fight over control of the sect, which drags Chen Yifan and Liu Yanyan in. He combines what he knows of modern technology with cultivation resources to raise his own power, and he calls up an army of zombies from the world he came from, so the fight becomes machines and technology against magic. His watch resonates with the spirit veins of this world at the same frequency, and that resonance is what explains how he crossed over.