Hogwarts: I'm More Than a Dark Lord

In 1892, in the Scottish Highlands, Hogwarts Castle.

Just as the freshly graduated William Richard “reluctantly” accepted the offer from Headmaster Blake to take the job of teaching Defense Against the Dark Arts—he traversed through time once again and found himself in London a hundred years later.

Upon receiving another owl from Hogwarts, he didn't hesitate much, and to continue learning his beloved magic, he once again enrolled as a rare fifth-year transfer student at Hogwarts over the past hundred years.

Albus Dumbledore: Although I don't know why William keeps murmuring things like “I held you when you were a child,” putting that aside, he really is a diligent and studious good child.

Sorting Hat: Az— Mmm...

Tom Riddle: Shut up! How dare you call that great one's name directly?

Harry Potter: Though Mr. Richard said he uses Unforgivable Curses as lighting spells and has built a tower of troll and goblin heads, I believe he must be a good person.