Class in Session! Defense Lessons 1

This was going to be a weird lesson... Not just because the classroom for it was in the cellar of the school, no. The hallway leading up to this door was rather long, with no doors to either side, and only the classroom at the far end - that alone seemed foreboding. In reality, it was simply a safety measure to make sure that any 'exhibits' from this lesson wouldn't slip away and cause chaos...
Because in this classroom, there was only one subject taught by only one teacher in the whole living world. This was the 'Defense Against The Otherworldly', taught by Zeref, the dark wizard, himself. Because who else would know more about things from different planes than a being born between them all?
Even the classroom seemed to have slightly less lighting than the usual ones, although that could also be from it being underground. The first year class that was about to recieve their first lesson would probably enter the room right about now and scramble to find a good seat, which either meant far in the back for deliquents or middle to front for people actually interested. Although that might not be the case in this class - after all, no other school in the whole world had this subject, so there were a lot of rumors surrounding it and the teacher.

And said teacher still had to yet arrive in his classroom. While students were usually expected to arrive ahead of time anyway, there was no sign of the teacher in the hallway either. Little did they know - he was already there, just a few rooms away in these 'catacombs' of his, as some liked to call them. In a room without a door, nonetheless - all to make it near impossible for a student to stumble across this room. Zeref was not an evil man, no - he was just quietly getting some documents in order right before class.
The problem was simply with the influence he undoubtedly had with time upon an area he lived in. If any student were to wander inside of his room, see a cosmic horror, and go insane? Well, then Zeref could probably hurry up to get out of Karakura forever before any of the authorities found out. The badges could protect a student from the aura emitted by the teacher, but that was about it. Now, said teacher with the deep, black eyes turned towards one of the walls, and...

In a black cloud surrounding his old location, Zeref disappeared... Just to just as suddenly re-appear. In the classroom, right infront of the class, stepping out of what could only be called a cloud of nothing but 'black' that let no light through. And with that, Zeref looked over the class... With a small, friendly smile on his face. Class was now officially in session.
"Good morning. Most of you probably don't know me yet, so we should get the introduction out of the way. My name, in your language, is Zeref. I'll be your teacher for the Defense Against The Otherworldly. If you have any questions about me, or this class, ask away. I'll use this first opportunity to answer as many questions as there are, there is no rush about starting on the subject matter."