KasiCair
I can't help but notice that the MC has a major case of Superiority Complex. He looks down on magicians. He looks down on devils. Now he looks down on wizards. Calling them 'weak chickens' when he's barely any better with him just entering High Class. Then he gets mad and complains when people look down on him when he does the same, all of the time. He is essentially an insecure hypocrite.
To be honest, I'm getting more and more frustrated. Starting with the Harry Potter arc, the plot doesn't move. You can even not read the last 10 chapters, but they are not there and as if there are fewer of them. Introducing the next chapter. GG sighed. End of chapter. I am very interested in the story itself, but with such chapters I want to stop reading. (English is not my native language)
One the things I think is accurate in the portrayal of the wizarding world in this chapter is their lack of common sense and attention to detail. Notice how no one realizes he was using magic without a wand, one of the things wizards consider to be a high class skill that only the best and oldest wizards are capable of. The whole Harry Potter arc does feel like filler and useless but we have years before any of the real DXD plot starts up. Having the author just do a time skip is possible but I think the reason for this filler is to show off Tom's magical capabilities in a safe environment, were the rest of the supernatural world won't really notice. Especially the Devil's.
I believe the reason the MC is acting this way is for him to have information about the people of the HP canon, after all although he seems to underestimate this magical community he doesn't take any action to alarm people about his power, and how this world has it too marvel mixed in it, it may be that he is worried that he may be the creator of the deathly hallows, as they can be made by a god of a pantheon or just to make his life difficult for lady death.