Okay, so I think the series title was something like "Loyal Traitor" and I think it was Korean but I can't find that so it's wrong.

The MC is a government official who is embezzling money as the kingdom falls, but the system calls him a loyal subject and pulls him into what's basically a kingdom building game so he can rank up the kingdom and avoid it falling. He has a helper/system avatar who I think is an angel.

He does missions where he goes back in time and possesses someone.

The first one he goes back and is a like a tribal guy. He uses an axe and sets the enemy village on fire.

Then in a later part he's a corrupt general and has to select whether the Prince or Princess is the heir.

He supports the princess, but figures out the General he's possessing was the one who schemed against her with the prince.

The Disloyal Subject Saves The Country?

fuck

That's the one. Thanks.