Implicating zeraora → legendary_pokémon
Link to implication
Implicating magearna → legendary_pokémon
Implicating keldeo → legendary_pokémon
Implicating meltan → legendary_pokémon
Implicating type_null → legendary_pokémon
Implicating silvally → legendary_pokémon

Reason:

It's a mythical Pokemon so it should be tagged as a legendary Pokemon as well. Same with Magearna, Keldeo, and Meltan.

Type:Null and Silvally should be tagged as Legendary as well.

https://www.pokemonlegendary.com/en-us/legendary-pokemon/
https://www.pokemon-sunmoon.com/ultra/en-us/gallery-detail-19.html
https://pokemonletsgo.pokemon.com/en-us/new-pokemon/