Spoiler warning! This article contains spoilers for the game.
Divaevus makes its appearance throughout the game as a legendary Pokémon under the control of Team Asgard/Olympus which possesses the ability to alter the flow of time because of its status as the "Divine Plate" of Arceus. With this power, Divaevus is able to enter the past along with any objects or living beings that it chooses to transport with it. It is for this reason that Odin/Zeus attempts to use Divaevus to go back in time and acquire enough power to defeat the protagonist and his/her allies.
However, even Divaevus is unable to give Odin/Zeus enough power to defeat the player, resulting in Odin's/Zeus's downfall. After the main antagonist is defeated, Divaevus disappears seemingly to never be seen again...
To battle and capture Divaevus in 1.4, one must reach Suzerain rank in the Challenge Championship, doing so will award the player the Burnt Photograph. Present this to the photographer in Nyasa Town's Past. Approach the Pokehadron Collider in order to encounter Divaevus.