Mated To my Professor

Check out strongest necromancer of heaven's gate, so far the mc's stuck to his necromancer and the writer improves on that class instead of adding another. So it fits ur requirements.

fie! leaveth this foul behavi'r to the abyss

What's 1 and 2.. Recommend me some

The story is excessively drawn out – and by that, I mean EXTREMELY excessively drawn out! What could have easily been summarized in just two paragraphs has been needlessly stretched across ten lengthy chapters, consisting primarily of nothing but side characters' speculation and their viewpoints.
.
Let me give you an example: The main character is about to be born, but instead of just telling us what happens, we spend two whole chapters hearing what the other characters think might happen. Finally, the main character is born, and then we get two more chapters where the other characters react with excitement, surprise, and more guessing. And to top it off, there's another extra chapter just to describe all the amazing things that occurred during the birth and another two chapters of excitement, surprise, and more guessing.
.
It's pretty much 10% story and 90% side character Bullsht.

the book is worth reading.