Em...idk how to feel about it? He was a normal person before he died(with a family who loved and took care of him and hospital staff that treated him kindly) but turned into an ultra edgelord after being "reincarnated" just because.....lost memories?? Aka, casual destruction of anything and everything. His humanity basically disappeared and has no qualms in killing whoever tries to "kill" him. Like, i understood why he killed those first 3 humans cus they did attack him out of nowhere but he felt no guilty conscience after. It's like watching someone kill bugs and wiping off the carcass on tissue and throwing it away in the garbage but not understanding why their colony go after them. It's that lack of critical thinking of the consequences. He figured out that the teachers would go after him for it but he still thinks that he was the one who was wronged. He just doesn't think killing people is all that, it's like sleeping for him.
With the cemetary part though, where those soldiers were sent to find out what was happening, MC went straight to killing just so he could test his new found techiniques just cus they were there to confront them...cus he assumed they were there to kill him. Just assumption.
The oracle was right, a disaster is headed for them.