Ben 10

Instead of a boy accidentally getting a super weapon and carrying that shit over 3 shows and a flop of a reboot, there were 2 Omnitrices and 2 Bens, twins, 1 woman and 1 man. These omnitrices were created by Albedo and Azmuth as friends and rivals trying to create the greatest sex toys, creating various criteria for a victory. Azmuth and Albedo wanted their devices to go to Max, but the results would get muddled, so they chose to give their Omnitrices to the Ben twins. The female Ben, F.B., (Use this as a reference for the rule 34 version: https://imhentai.xxx/gallery/1343503/) got sent Azmuth's Omnitrix he called the Sexotrix, a butt plug Omnitrix that turned the user into a sexy/stud version of that alien, whether that be a bimbo, a milf, or other body types given to the altered alien species. The male Ben, M.B., (Use this as a reference for the rule 34 version: https://imhentai.xxx/gallery/1275086/) was given the Nemetrix by Albedo, an Omnitrix that would have become a version of the Omnitrix but filled with predators instead of sentient species. In this rule 34 version of Ben 10, the Nemetrix created sexy monster girl versions of the aliens as a momentarily and separate entity, who would be created based on the species' wielder's preferences and utilise their DNA to help tailor these traits, copying the owner's mind and fusing with summoned alien with the copy, creating a harem of idealised women in both body and personality who genuinely loved the user.

While Azmuth wanted his Omnitrix to aid the wielder in their dopamine grind as if it were a strap-on, Albedo's created a harem he could summon on demand. They were different devices but their creators wanted to give both to Max because Max was still a living legend and a major part of the Plumbers in this world, but he's also a futanari (Use this as a reference for Max's futa version in this story: https://imhentai.xxx/gallery/1125287/) with a LOOOOOOOONG list of sexual partners.