MTL - The Lady’s Sickly Husband - ~ Recommend yourself to finish the mortal

Friends, standing before you is:The Master Of Gacha;The Bug Catcher’s Bane;The Nightmare of Every Youngster;The Idol To Countless Boys And Girls;The Second-in-Command of Team Rocket;The Uncrowned King of the Underworld;The Youngest Champion In History;Master Of All Types;Luo 'The Shining Light Of The League' Yuan!

Instead of causing chaos with my knowledge of the original work, I assisted the protagonist.

I successfully completed the story and now planned to retire and live peacefully.

However, it seems the protagonist still needs my help.

An academy professor? That’s nothing much.

But why is the state of the academy so strange?”

Darkness is coming, and crisis is everywhere. In this long dark and desperate night, do you want to see a bonfire with warm words? We are that light.

We don’t want to be the little bully who guards one-third of an acre and eats canned food.

We don’t want to drive the harem on a great escape from east to west.

We don’t want to be a bunch of rats guarding rancid cheese in the gutter.

We don’t want to see the panic on your faces and the desperation in your screams.

So we stand up, fight for ourselves, fight for you, fight for humanity!

As long as we are here, the flames of war will never be extinguished.

We light a warm bonfire in the dark night, and watch the dawn with the brilliance of life.

We are the shield of the earth, the patron saint of mankind!

- Description from novelbuddy

Ian thought he was just a little wizard with a tiny bit of talent [cheat], and that hard work would make him stronger. However, as the story progresses, he gradually begins to discover that the teachers who have been teaching him magic are either once-famous strong individuals or characters mentioned in various legendary stories.“Standing before you is the noble apostle of the Misty Illusion Realm, the joint spokesperson of the Old Dead, and the designated successor by the founders of Hogwarts!”“What? That noseless freak wants to cause trouble? He must not have heard of my original magic spell that’s even recorded on the Chocolate Frog's famous collector's cards!”“Dumbledore Summoning Spell!”“Dumbledore Berserk Spell!”