10 Billion Days & 100 Billion Nights by Ryu Mitsuse

Jesus of Nazareth is a shifty fella who exhibits symptoms of Tourette's syndrome, won't make eye contact with anyone, mutters a lot, and shoots fire out of his fingertips in his attempts at killing Plato, Siddhartha, and Asura, because, you see, Jesus is working for the Bad aliens. Yes, the same aliens who may have been behind the building (and sinking) of Atlantis.

Siddhartha might have told people he was leaving home to go meditate under a Bodhi tree--but it's just as possible that he hopped into an intergalactic bubble with a few Good aliens to take a tour of the Universe (or Multi-verse), so that he could sit on the blue sand shores of Tisuta and contemplate the path to Enlightenment while watching an Inter-Universal war taking place in the sky above him.

Plato is just looking for some Answers. And Asura has been fighting this war for millions of years across several galaxies with her elephants and her generals and she's starting to wonder about the Why and the Who of it all.

Ryu Mitsuse wrote this in 1967. It was translated into English in 2011. According to its cover, and every mention of it that I've seen, it has been called the greatest Japanese Sci-Fi novel of all time (I haven't done any digging to solve the ad authoritatum problem of By Whom). It's short, to the point, and full of Stuff Happening, once you get past the first 20-some pages of Earth from the apparent perspective of seafloor protozoa and/or possibly alien eel-type creatures.

I was especially gratified to read the brief author's note at the end, wherein he lists the Sci-Fi books that he came across in his teens and that changed his world, and what he learned from them. One of these was new to me and I'm currently enjoying it: City, by Clifford Simak, which gives us the legends of our world told from the perspective of Dogs, who are all that are left here a few hundred years from now.