What if a religion had been founded around Aristonicus as an anti-Roman avatar of a god? Below is an in-universe writing that offers an answer. 
"While the growth of Soterism seems inevitable to modern readers, a close study reveals its complex evolution, as well as its near-extinction on multiple occasions, over the course of the ages. In 625 AUD (129 BCE in OTL), an obscure pretender to the Pergamene throne was executed by the Romans after a failed revolt. The so-called Eumenes III, better known to the world as Aristonicus, seemed destined to fade into the annals of history along with other unsuccessful revolutionaries. Fate, however, had other plans for him. Word spread throughout Anatolia of Aristonicus’ devotion to the poor and downtrodden, as well as his plans to establish a utopian Heliopolis, after his death. By 645 AUD, the rumors would take a dramatically new turn when an ex-Orphic priest named Cyrillus claimed that Aristonicus was divine. Cyrillus also named the would-be king a “soter”, or savior, of all of humanity who would liberate the divine sparks from their fleshy prisons. With its blend of mystery religion, Platonic theory, and social agitation, Soterism exploded in popularity over the next century in the face of Roman opposition (honoring a foe of Rome as a god). In the wake of the Roman Republic’s collapse, many Romans would promote Soterism as their faith. Even then, few people imagined that Soterism would become a major world religion…"
"While the growth of Soterism seems inevitable to modern readers, a close study reveals its complex evolution, as well as its near-extinction on multiple occasions, over the course of the ages. In 625 AUD (129 BCE in OTL), an obscure pretender to the Pergamene throne was executed by the Romans after a failed revolt. The so-called Eumenes III, better known to the world as Aristonicus, seemed destined to fade into the annals of history along with other unsuccessful revolutionaries. Fate, however, had other plans for him. Word spread throughout Anatolia of Aristonicus’ devotion to the poor and downtrodden, as well as his plans to establish a utopian Heliopolis, after his death. By 645 AUD, the rumors would take a dramatically new turn when an ex-Orphic priest named Cyrillus claimed that Aristonicus was divine. Cyrillus also named the would-be king a “soter”, or savior, of all of humanity who would liberate the divine sparks from their fleshy prisons. With its blend of mystery religion, Platonic theory, and social agitation, Soterism exploded in popularity over the next century in the face of Roman opposition (honoring a foe of Rome as a god). In the wake of the Roman Republic’s collapse, many Romans would promote Soterism as their faith. Even then, few people imagined that Soterism would become a major world religion…"