@Merilirem
Those people tend to stop reading after just a few chapters. Those who continue reading, while leaving really nasty posts, are usually pretty safe to block. You won't see their comments anymore.
Mangadex suddenly becomes such a noticeable nicer place if you only block a couple of them, it's amazing!
On the other hand, this isekai does feel pretty generic, even if the premise is new. It's still only starting off, however, so I'll give it another couple of chapters.