The supporting character's harem is very normal - Chapter 358 Sorry… Lathel… I’m really sorry.

Xzavier was super one of the special forces and then transmigrated into the isekai world of magic. It was full of things he couldn't figure out. The magic, elves, orcs, alchemy... However, even in different worlds, humans were always the same. After all, human nature always remains consistent. He encountered a deadly threat, not from a dangerous environment but from his own kind. Fortunately, he had a military system. He could use the weapons he had always been familiar with.The collision of magic and modern weapons, the fierce confrontation between old and new thoughts, the sinister conspiracy and trickery...How should he survive in the strange world?

Luo Yi, a high school dropout in his original world, was isekai’d into the world of the Witcher 3. Starting out as a weak boy named Roy in the village of Kaer, Lower Posada, he was determined to grow stronger, no matter what it took. The first step toward becoming a legend was to kill. And his first kill was… a rooster. ‘You gain 1 EXP.’ Of course, Roy had his own cheat system like all the other isekai protagonists. His first step to becoming a legend started now…

Humanity’s home is no longer Earth. Intersellar travel is now a common occurence, and technology has replaced blood and flesh.Luka, who grew up in the slums, has turned fifteen and taken the selection exams. His aptitude is of the “Imperial Guard.”