The Isekai Milf harem! - Chapter 15: Ch) Sixsome.

This story revolves around a boy who was sent to a dark, mysterious parallel world in the body of his beautiful senior sister known as Lily. The lone girl ran into the night parade of a hundred ghosts the very day she arrived; seeking survival amongst the warrior’s dispute in a chaotic world, and forging her own demon sword! This is an unimaginable other world adventure!

Jung Sunwoo was an average man. He had just taken his first job at W&U, a celebrity management company, as a manager. He could finally achieve his dream of being the manager of a world-famous actor or actress. On his way to work, he fell into what appeared to be a lucid dream about his future. As he went on with his day, he realized it may not have simply been a lucid dream.

Video game streamer Jing Yu, momentarily misstepped, and found himself in a strange professional gaming team.

Solo laner: Even if I have my eyes closed, asleep, dreaming, I can still kill you all!

Mid laner: Retreat? Not going to happen. Even if I only have one drop of blood left, I’m going to kill you all!

Marksman: Attack range advantage? I like to battle close-range! If you aren’t a coward then don’t run, let me kill you all!

Support: Support? As if! Wait until I switch to an AD build, then I’m going to kill you all!

Jing Yu: ……

Jing Yu: All of you, retreat! I’ll be the one to kill them!

- Description from Novelupdates

She is the slow-witted idiot of the Prime Minister’s Residence. Everyone bullies her. He is the most respected and unfeeling Prince, with frightening ability and absolute envy! Together, they are conferred an imperial edict of marriage.