In Japanese, Dark type is actually Evil type, while in the English versions, Dark loosely means the same thing. This is most likely why Fairy Type is strong against Dark type, why Light type doesn't exist, and why Dark type moves have names like Baddy Bad. :P
The moves were likely created to make your starter Pokémon more OP and Fun to use, as well as adding more ways to Heal Status, set Screens, heal, etc. :P