I find it interesting that you introduce nen beasts or spiritual concepts into the world of MHA and how those energies affect those around the protagonist. As for the slow development, I don't mind. There are people who complain about that, but they forget that all the plots of Boku no Hero happen in the protagonist's first year as students. Personally, I don't care as long as it's well written and understood. As for the harem, it doesn't bother me. After all, I'm a veteran of DXD stories, where they exaggerate the harem. Take that gentleman, his 5 stars.