The mysterious "Ultra Bonus" reward was announced at the beginning of this summer as part of Pokemon Go's worldwide tour of live events. Each live event (a Safari Zone in Dortmund, Germany, Pokemon Go Fest in Chicago, and a Safari Zone in Yokosuka, Japan) came with a Global Challenge that required players around the world to collectively complete 1.6 million Research tasks over a two day period.
The new Ultra Bonus Unlock will include Mewtwo Raids, Articuno, Zapdos, and Moltres will be back to battle, as well as Farfetch’d, Kangaskhan, Mr. Mime, and Tauros becoming available through egg hatching.
For each Global Challenge completed, players got a number of in-game bonuses over the next week, along with a special mini-event that allowed players to raid for a specific Legendary Pokemon Go has stayed mum on what exactly the Ultra Bonus is, leading to plenty of speculation by fans.
The two most popular theories to date is that the ultra bonus will either begin the rollout of "Gen 4" Pokemon or somehow add the Mythical Pokemon Deoxys to the game. Deoxys and its various forms have been in the game's code for months, and players have wondered when this powerful Pokemon would finally be available for players to capture.
First, starting September 13 at 1:00 P.M. (PDT), Trainers all over the world will be able to encounter three Legendary Pokemon originally discovered in the Kanto region!. Articuno, Zapdos, and Moltres will appear in Raid Battles until September 20. And if you're lucky, you may be able to encounter their Shiny forms! Also, Pokemon originally discovered in the Kanto region will appear more frequently all over the world and show up more frequently in Raid Battles until September 30!
One theory suggests that the Ultra Bonus would unlock a "Mewtwo Day" event giving all players a chance to capture the Legendary Pokemon (who is currently only available as a EX Raid Boss), which in turn would give Pokemon Go an opportunity to add Deoxys as a new EX Raid Boss. This would give those players who haven't gotten an EX Raid Pass a chance to finally capture Mewtwo, while keeping the controversial Raid system relevant for the next year or so.
The yellows of Team Instinct finished in third place but did manage to score a victory in South America. The reds and yellows will be hoping for some revenge in the next Community Day event, which takes place on September 22. The September event focuses on Chikorita, which is ideal if you're yet to evolve a Bayleef or Meganium.