Steel Covenant

"Qiao An of the Honours Class in the Combat Armour Academy, you have failed the mech compatibility test and have been demoted to the logistics class of the outer academy."
Three hundred years after the apocalypse, the human world lay shattered. A young man, Qiao An, burdened by immense debt, unexpectedly discovers that he has already bonded with not just one, but multiple sets of top-tier Combat Armours.
"Black or white—what's your choice?"
"I'll take them both!"
With the strongest combat armours in hand, making money will become easier than ever.
"Saving the world? Nah, that's none of my business."
"What? Did you say all my debts will be forgiven? Wait, hold on—!"