After you defeat Volo, Cognita will send you on a quest to catch the nature trio (Landorus, Thundurus, and Tornadus). After doing so, she will allow you to catch the fourth member of the group, called Enamorus,. A Fairy/Flying type, with it's own Therian Form based off a turtle. This game is when all four genies collected their respective signature moves Bleakwind Storm (Tornadus), Wildbolt Storm (Thundurus), Sandsear Storm (Landorus) and Springtide Storm (Enamorus)
In the Turnback cave, located in the Cobalt Coastlands you can find Giratina to fight and catch for yourself.
Additionally, Laventon will allow you to collect the other two starters you did not pick at the beginning of the game, on the beach. (For example, in my newest play through I picked Cyndaquil so I would collect Oshawott and Rowlet)
