Nanomancer Reborn - I've Become A Snow Girl? - Chapter 25: Shadow Temple p4

(Warning: Harem, if you don’t like it, please refrain! Boldly breaking taboo ethical norms, not letting go of any beautiful women encountered!) A young nobleman with a delicate constitution, pure and kind, has always been protected by everyone. However, after two months of military camp life, he began to change for the worse. With unbeatable power in his hands, he became lawless, targeting countless beautiful women in the city. In his eyes, every beautiful woman is like a delicate flower. He wants to gather these tender flowers around him, then extend his strong wings to shield them from any harm...

Reborn as Red Army Misha!

- Description from novelbuddy

There was a Senior Brother and a Junior Sister. One of them was transmigrated to this world and had cheats while the other was the reincarnation of a Great Emperor.