Hogwarts and the Legacy of the Holy Grail War

Ethan, a transmigrator who was admitted to Hogwarts by special exception, discovers that his talent seems just a tiny bit higher than everyone else's, and that he can even use the legendary ancient magic.

And so begins his career of making trouble in the magical world.

What's this? A black-hearted Holy Grail tainted by dark sludge? I'll chop it up!

What's this? A bald dark wizard with no nose? I'll cut him down!

What's this? The vengeful spirit of last century's big bad? I'll lay it to rest!

What's this? An ancient treasure hidden beneath the school? Mine now!

After a battle that wasn't particularly intense, Ethan looks down at the various enemies lying before him with disdain.

"I hadn't even started trying, and you were already down."

"Lumos to blind them, Expelliarmus to disarm them and remove the threat, and Stupefy to knock them out and keep them under control. What a perfect combo!" Ethan, the former head Auror who retired early and now loafs around at home, shares his tips with a reporter.

"And what if that combo doesn't work?" the reporter asks.

"Simple, my friend." Ethan's smile doesn't waver as he answers in a relaxed tone.

"Just use Avada Kedavra on them."

Note: This book contains plenty of fanon, out-of-character portrayals, and heavily altered timelines, among other things. Read on at your own risk.