Latias

While Latias isn't commonly used, it has a niche in AG thanks to its typing, ability, and Soul Dew, allowing it to check Primal Groudon and Kyogre as well as beat Adamant Mega Rayquaza one-on-one and threaten weakened Extreme Killer Arceus. Its ability to wall common Stealth Rock setters such as Primal Groudon and Arceus-Water makes it a useful Defogger. Because of this, Pokemon such as Ho-Oh and Yveltal appreciate the support it provides.

However, Latias loses to a large number of Pokemon including Darkrai, Klefki, support Arceus, Ho-Oh, and Yveltal. Moreover, it often gives Pokemon a free turn, which can give Darkrai or Klefki a free Substitute, allow Xerneas to use Geomancy, or let Arceus get a Swords Dance or Calm Mind off, especially after Latias has used Draco Meteor. Latias also faces tough competition from Pokemon such as Arceus-Dragon and Arceus-Water, both of which boast access to Defog alongside similar bulk and resistances. It should be noted that they aren't entirely similar, though, as Arceus has better Speed and Defense, while Latias offers better utility and offensive options. Latios also offers some competition; however, Latias's higher special bulk is generally more useful than Latios's stronger offensive stats.