Devouring Contractor of the Doomsday

In the apocalypse, Zhou Yuan went through seven years of hard work, and his teammates, relatives, lovers, and brothers all died tragically in front of him. Waking up after an unexpected death. Go back 7 years ago and witness the outbreak of the apocalypse again. Awakening the devouring contract system in the previous life in this life and becoming a devouring contract master, how to become stronger before death. Guard the regrets of the previous life. Devouring is a contract, killing is growing