MTL - Into Unscientific - Chapter 106 strange way of delivering water

Emperor Ian Veroshion, the first noble mage, was betrayed and executed. Cursed to never be reborn, he awakens a century later as the illegitimate son of a disgraced ducal line, destined to be a hostage in a barbaric land. Stripped of his magic and his throne, he must navigate a world vastly different from the one he ruled, facing political machinations and a resurgent monster threat. But the embers of his past life still burn, and Ian will not surrender his legacy. He will reclaim his name, his magic, and perhaps, even his empire.

Sequel of Allison, taking place about 17 years after the original series.

The most unlike Slytherin.

There is a saying in the Slytherin common room, “The little wizard who disobeys will be eaten by the Night Stalker.”

He is the master of the stars that shines at Hogwarts, the Night Stalker who is feared by his enemies.

The glory made him the pride of Slytherin.

When the Dark Lord arrived, he said those words,

“Weapons, I need a lot of weapons.”

With a staff in his left hand and a sword in his right hand, everyone would shout for him: “Damn the Sorting Hat, is this Slytherin?”

When the stars return to Hogwarts, John Wick’s light will shine on the entire wizarding world.

- Description from novelbuddy

Another entry in what you can call the Proto Harem Series: the books written before the Harem Series that take place in the same world.

It’s about a swordswoman whose student is captured, so she goes to rescue her.