In the Last Days, Wouldn't It Mean That People Are Invincible If They Can Upgrade?

The Demonic Virus has been raging for five years, turning 90% of cities around the world into wastelands. Wherever the zombie wave passes, life is devastated! The time traveler Mu Tian struggled for four years in the apocalypse, almost forgetting that he was a time traveler, but in a demon attack, the [Demon Growth System] that was four years late finally awakened - devouring demon seeds to gain energy, his body heals itself, he has steel and iron bones, and he cuts down enemies. His half-human, half-demon physique makes him the most special existence in the wasteland! Afraid of pain? Fear death? Want to lie down? In this wasteland, the only way to survive is to devour and become stronger! Mu Tian clenched his fists: "Either become the king of the wasteland, or become the ration of the demon species - I choose the former!"