Because of Gamefreak getting rid of the national dex, older pokemon started to get new Pokedex that explore their background instead of copy and paste text from their first appearance. Post your favorite one from anything from Gen 7-9.

Mine have to be Noivern's from Gen 9 where it is said to be timid and scared during the morning but at night it's a terrifying monster that no one want to fight it, not even Hydreigon, a Pokémon that is said to be incredibly violent and capable of destroy cities and village until nothing is left.