Yeah could've just made Mugo go faster there especially since he is so powerful and the little creature was there, feels like it happened just for extra unwanted nsfw
It's been having rape since their first sex scene, I don't know why it only strikes you now. But in terms of plot this chapter is actually gold, there are many answers given and clues as to where the Mugos currently stand in their dissociation journey.
But it's definitely not for everyone, so maybe dropping it is a good option for you.
No it happened because there were many important details to drop in this scene for the story progression. Here, an explanation of sex usage in this story:
https://www.mangago.zone/home/mangatopic/19227055/
This last chapters were unreasonable, unnecessarily bad, like what the fuck did rape add to the story or why was this fuck needed, it had more potential.