No Brain And No Brawn.

She is threatening him. In this world, it doesn't matter that you worked for something and that you deserve it. You get what you can take and keep what you can protect. Can the Reaper protect what he will soon get? 

This is wealth that will entice demon gods. They might not be able to do anything about it but Demon gods will surely kill for it. It is in the Reaper's best interest to bribe them so that they will keep their mouth shut. Being headstrong is just folly.

Aeternus didn't address her veiled threat. He ignored her and picked up all the Celestial Godhood. Then he turned his back on the two of them as if they weren't there. He began to fly in the direction of the divine city where the rest of his loot is. 

The divine city is far away from Armageddon. It is a small landmass where divine lords and visitors to the divine plane stay. Above the divine city are the divine kingdoms.