After their previous defeat by the two Sonics, the older and younger Eggmen find themselves stuck in a white void with no way out. However, they find shelter thanks to another Dr. Eggman from the erased, 2006 timeline, who's spent a great deal of time there on his own. The three mad scientists come up with a plan, recruiting their other selves so that they might combine their brainpower, and get rid of Sonic and his friends once and for all.
A Sonic fan-fic that pulls different versions of Eggman throughout the franchise's history into a room, letting their schemes collide and interfere with one another. Because the premise involves multiple versions of Eggman meeting, the doctors were given their own names, identifying which eras they emerged from: Eggman Prime (from the 3D games), Robotnik Prime (from the early, 2D ones), Eggman Solaris (from 2006), Eggman Nega (from the Sonic Rush Series and Sonic Rivals), Eggman Boom (from Sonic Boom), and Robotnik XL (an amalgam of various Robotnik characterizations from the 90's). As such, several different Sonic canons are represented, along with many references to other games.
The fic was uploaded to FanFiction.Net on February 17th, 2016.
Eggman Generations has the following tropes:
- Composite Character: Robotnik XL is a conglomerate of the various characterizations of Robotnik from the Western 90's cartoons and comics: Adventures of Sonic the Hedgehog, Dr. Robotnik's Mean Bean Machine (itself a game based on Adventures), Sonic the Hedgehog (SatAM), Sonic the Hedgehog (Archie Comics), and Sonic the Comic.
- Future Me Scares Me: Robotnik actually loathes his older self, even starting to understand why Sonic fights him all the time if Eggman is the person Robotnik grows up to be.
- My Future Self and Me: Eggman Prime questions whether he, himself, shouldn't exist, since his past self doesn't want to be anything like him, but quickly writes it off.
- Temporal Paradox: Enforced, by the nature of two Doctor Eggmans from the past and future existing in the same time and space, and later, they encounter the Eggman from the erased timeline of Sonic 2006.
- The Multiverse: Implied by the premise of the modern and classic Eggman encountering other Eggmen from different dimensions, and in the case of Eggman Solaris, an erased timeline.
- Villain Protagonist: The main characters are all versions of Eggman from other timelines, games, and dimensions entirely. The story is about the doctor and his allies, rather than Sonic and his friends.