Three years, then another three years...
Chen Mo is a human spy embedded among the demons.
Starting as a demon soldier, he gradually put down roots and climbed his way up to become a demon general.
Chen Mo: "Hey, hey, when are we going to close the net? If you don't do it soon, I'll become the Demon King!"
His superiors: "Wait a little longer. Something's come up on my end."
No, what do you mean, "wait a little longer"? If you wait any longer, the Demon King will come looking for me.
And the Demon King really did come looking for him.
The Demon King: "I think you have great potential. Go on, here's your new identity. Infiltrate the human race."
Chen Mo: "Wait, why me?"
The Demon King: "Because you look the least like a spy."
"I..."