Military System In Isekai Of Magic

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?
......
It is a harem novel and will arise some mature content, and I'll concentrate on some fighting plots. I like both of them, so stay tuned for more amazing stuff.