Review Detail of BeHuaMuH in I Reincarnated as A Little Girl?!

Writing messy, at least at start. Mc is idiot, when he can cast some meteor or other crazy spell he just make faces and knoked out =/ mc power level is all over the place, at one moment he goes to sleep, coz he tired, even without saying to his maid vital info(like damn plot to kill him) then awakens tied and ready to be killed, next moment he can go like week with no need for sleep, then again he tired and need sleep. One moment mc kills some mobs with magic like a boss, next chapter cant do crap against humans =/ and there many points like this, one moment he kill, next moment goes crap like oh its young guard he has all his life ahead, and oh all castle guarded by 15 yo so cant kill anyone or just destroy whole thing. Summary: its bad read