It is always best to start the LN or WN from the beginning, cause the manga always skips a lot of details and even story points that seem insignificant at first but become important later
Why do i feel like there's something missing... wasn't the demon general there tricked into exile and MC and wifey decide to take her and her two subordinates into their care....?
This was basically a flashback episode where that demon commander was sent back after chapter 10. I guess the author wanted to show what happened to the other people that got transported and what happened to Grinzel.
@no168_92
First half of the chapter is flashback/what happened between chapter 10 and 11. - pages should have a transition but don't... ex: black border or blank boxs showing passage of time...
Last bit of the chapter is current time.