Marandahir
Crown-Forester (he/him)
Yet Mitra and Varuna are constantly called Asuras in Hinduism – and are considered Good Gods. Asura and Daeva are different families of Gods in the Rig-Veda. Most Asuras became demonized in Hinduism, but Asuras as a whole did not. Most Daevas became demonized in Zorastrianism, but some deities that were demonized like Indar (Persian Indra) retained their noble characteristics in another variation (Indra Verethragna -> Verethragna/Vaghan, a heroic Yazata who helps the people overcome obstacles much like Indra Verethragna does in the RigVeda).Instead of Big Evil, many (though not all) religious/spiritual traditions tend to have Big Scary.
Hades and Persephone weren't evil. Indeed, by the standards of both their day and ours, they were quite affable. Hades welcomes heroes into his home, negotiates fairly, and even his kidnap of Persephone is a fairly normal thing to his culture—and, more importantly, he has very few myths (none, in some traditions) where he's a philanderer, while Persephone genuinely co-rules the Underworld with him. She's not the goddess of spring, she's the goddess of the underworld. But invoking her name or Hades' was a dangerous, risky thing. You didn't do so lightly. They were scary as hell, pun absolutely intended.
Ironically, despite the Eastern mythological association with greater moral greyness, Vedic and Shinto deities do include many outright "demons" or otherwise explicitly malign, evil supernatural powers, some of them at the level of "gods" as the West would understand the term. Of course, there are also scary "good" gods like Shiva and Kali (and especially Kali's "war" aspect, Durga.) But the "daevas" are evil in Zoroastrianism, while the "devas" are good in Hinduism and the asuras are evil. Etc.
Evil as a supernatural force is complicated!
Note that Ahura is used only for Mithra and Ahura Mazda (aka Varuna) in Zorastrianism and sometimes a third member (either Apam Napat or Aredvi Sura Anahita); the other "good" Powers in Zorastrianism were relegated from deity level to Angelic Yazata, but have rough analogs amongst the Hindu deities and misc. Powers.
So it's not as simple as an early Indo-Iranina split on the morality of their pantheons; it's more akin to religious reforms that caught on later.
Also, notably, the Aesir are etymologically linked to the Asuras, which just generically means "Lords", while Divine and Diva and Deus and Dione and Diana and Day and Dagda and Zeus and Jupiter and Tyr etc are all linked to Daeva originating in Dyaus – Daytime, but eventually generalized to "God" or "Divine Being."