Project Deca/Worlds

Earth-1121-A
Earth-1121-A, also known as the World of Team Tennyson, is an alternate counterpart to the Earth seen in Ben 10 Team Tennyson. In this world, Ben never lost the Omnitrix at the end of Alien Force, and has gained new aliens such as Angelion and Heatspecter. New villains also appear in Ben's rogue's gallery, the most prominent here being Veggie King and Timeking.

Earth-1116-A
Earth-1116-A, also known as the "World of Multi Trixes", is an alternate counterpart to the Earth seen in Ben 10: Multi Trixes. In this world, the timeline splits off at an unknown point in Ultimate Alien, followed by Ben getting a new Omnitrix resembling the Alien Force watch, and Gwen and Kevin receiving Omnitrix-like devices of their own. Eon returns as a primary threat to this world and seeks to unite the powers of all three Omnitrixes to become all-powerful.

Earth-512-A
Earth-512-A, also known as the World of MEGATRIX, is an alternate counterpart to the Earth seen in Ben 10: Ultimate Alien MEGATRIX. In this world, Ben doesn't lose the Ultimatrix at the end of Ultimate Alien, instead gaining an upgrade for it that turns it into the MEGATRIX. The MEGATRIX receives the ability to transform Ben into an Anodite, but the Anodite sample ends up going rogue and fleeing his roster, naming itself "Purponite" and seeking to subjugate humanity.

Earth-19-A
Earth-19-A, also known as the World of Young Plumbers, is an alternate counterpart to Earth-19. The events of the main Ben 10 series remain largely unchanged in this world, with the plot's focus being placed on students attending a Plumber's Academy. In this version of the world, several students of the academy, Scott, Peter, and Bianca (who call each other Sci, Paper, and Bink, respectively) are caught up in events regarding the awakening of the ancient demon lord Rigon, the personification of hate.

Earth-50-A
Earth-50-A, also known as the World of Protector, is an alternate counterpart to Earth-50. In this world, the events of Omniverse never happen, with Ben retiring from hero work for about a year before receiving a new Omnitrix called the Infinitrix. Unfortunately, his world's Azmuth is killed shortly after, and Ben loses his fighting spirit, going back into retirement.

Earth-98-A
Earth-98-A, also known as the World of Evolution, is an alternate counterpart to the Earth seen in Ben 10: Heroes of Evolution. In this world, Ben again retains the Ultimatrix at the end of Ultimate Alien and the events of Omniverse never take place. Instead, Ben forms connections with the Bellwood Police Department and gets called on to help with cases involving alien activity. This places him in the sights of Devil Watcher, a mysterious hacker who consistently pulls the strings of cases while taunting Ben and the police from afar.

Earth-114-A
Earth-114-A, also known as the World of Horizons, is an alternate counterpart to the Earth seen in Horizons. In this world, the events of the Ben 10 franchise never take place. In the mid-2000s, a mysterious comet crashes in midwest America, irradiating most of the country with energy that plants alien DNA into human genetic code. This DNA lies dormant until the host suffers a traumatic event, at which time the DNA will merge with said host, creating a violent mutant with superhuman abilities. The effects of the comet and control of the mutants are researched and handled by KafKo, a secretive organization with ties to several government agencies.

Earth-83
Earth-83, also known as the World of Tech, is the Earth seen in Not Applicable and the Tech 10 franchise. In this world, the events of the Ben 10 franchise take place as normal, but several other universal threats arise that are handled by heroes largely unrelated to Ben and his escapades. At the point relevant to Project Deca, all the heroes of the world have seemingly been killed, and the universe itself is about to be reset due to a failsafe created by the Celestialsapiens, wiping them all from existence. Something is preventing that reset from completing, however, leaving Earth-83 in a state of limbo Attai needs to fix before he can scan it.

Earth-1010-A
Earth-1010-A, also known as the World of Revolution, is an alternate counterpart to Earth-1010. In this world, Ben defeats an alien warlord known as Apollo after the events of Omniverse in a convoluted mess of timeline tom[frick]ery. Not much time passes after that before more timeline tom[frick]ery occurs, this time spurred on by a Chronosapien named Timekiller, resulting in Prime Ben and the Ben of the 2016 reboot, Delta Ben, switching places as Timekiller enacts his villainous schemes.

Earth-13\5\20\1
Earth-13\5\20\1, also known as the World of BTFF, is the Earth seen in BTFF RPG and its sequels. This world, for the most part, mirrors our world, and is located so far away from the rest of the multiverse that it's almost impossible to get to or leave, even for a Timewalker. Most significant events take place in a metaphysical wiki plane almost as detached from the real world as the users of the actual wiki. A user named CaT (who is way past his prime) wastes his time making theories about the biology of aliens in the Ben 10 franchise, an endeavor almost as frustrating as it is pointless.