Hinduism/WMG

Vishnu is a rock star.
He's got long hair, dresses in colorful clothes, rarely wears a shirt, and his multiple arms allow him to shred chords unlike any mortal man. Plus, who else but a rock star could get away with wearing live cobras as jewelry?
 * Except that Shiva's the one with cobras. Vishnu rides a multi-headed cobra.

The Hindu gods are either Eldritch Abominations or hallucinations brought by a lot of something similar to LSD.
Just look at the appearances of their gods. This Troper swears to the gods that they look like what would you get if you tried hallucinogens.
 * Most gods in mythology fall either as superpowered humans, eldritch abominations and/or anything in between. As far as Hindu gods go, their most unique trait is mostly being depicted with multiple arms. If you want REALLY weird gods, go check Malagasy or Easter Island mythology.

There is only one soul in the universe.
There's nothing tying the gods to our timespace. Now if they can exist outside our time, nothing mandates that reincarnation should be linear in our time. This would be the ultimate karma: everything you do to others you actually do to yourself!

The Hindu gods have converted to Buddhism
Amaterasu, Tengri, etc., have all done so in Mahayana Buddhism, so why not the Hindu gods?

Indra died.
Buddhism claims that gods live for only around 30 million years, and Indra has faded out of importance since early Hinduism.
 * Hinduism, however, makes no such claim. In the Bhagavad Gita, it's flat out stated that the Hindu God (and his infinite forms such as Vishnu, etc) are eternal. Besides, there's probably some disagreement within Buddhism on this issue.