|Previous Affiliation||Aizen's Army|
|Previous Partner||Sosuke Aizen|
|Base of Operations||Mobile|
|Weapons||Various Chronokinetic Weapons|
|Relatives||Ben Tennyson (alternate counterpart)|
At some unspecified time, Eon approached Sosuke Aizen and the two made an alliance, though the exact terms of this alliance are unclear. When Ulquiorra Cifer and Yammy Llargo return from a mission to Karakura Town in order to "test" Ichigo Kurosaki, Eon is infuriated to learn that Ben Tennyson has gotten involved. He emerges from next to Aizen's throne and explains Ben's origins, identity, and powers to the confused Espada and rogue Shinigami, adding that Professor Paradox had likely been responsible for Ben's involvement. When Aizen shows signs of nervousness after learning of Alien X, an amused Eon explains that the form is all but useless to Ben and that, despite his powers, Ben is not a great threat to their plans for the moment. He also laments that if Ben had been sent to Hueco Mundo instead of Karakura Town, Aizen could have manipulated Ben into joining him (an allusion to the original timeline). Aizen then asks Eon to explain Ben's origins and the powers of all of the alien forms he currently has access to.
After Grimmjow Jaegerjaquez returns to Las Noches following a failed attempt to eliminate Ben and his friends, Eon notes that Ben has become stronger and less arrogant, and that if he and Ichigo team up more often, they could become a grave threat. Aizen acknowledges that such a team-up would be formidable, but remains confident that it will not be enough to stop him; Eon coldly warns Aizen that the latter's arrogance could be his undoing.
Invasion of Las NochesEdit
End of the AllianceEdit
When Aizen is ultimately defeated and sentence for 20, 000 years, Eon arrives and removes the wrappings from his face. Eon then berates Aizen for his carelessness and arrogance. He then rips it the Hogyoku and destroys it with his chronokinesis, stripping Aizen of his immortality, and ultimately slits Aizen's throat.