He's the God of Discrimination, Zika /s.
Seriously though, Ryuuma was called the Sword God, Zoro said he wanted his name to reach the Heavens and wants to be the King of Hell, since the first mate can be a dark reflection/side or shadow of the Pirate King/Captain or whatever, (Rayleigh the Dark King, Beckmann got referred to as the moon or dark side of the moon to Shanks or something), then Zoro could end up becoming a God in one way or another, I mean if Usopp can be called a God in the story, why not freaking Zoro?!
Oda has been referencing Buddhism and thus Hinduism with Zoro too and when you look what Asuras are/mean, things get very interesting.....
https://www.britannica.com/topic/asura
asura, (Sanskrit: “divine”) in Hindu mythology, class of beings defined by their opposition to the devas or suras (gods). The term
asura appears first in the
Vedas, a collection of poems and hymns composed 1500–1200 bce, and refers to a human
or divine leader.
Its plural form gradually predominated and came to designate a class of beings opposed to the Vedic gods. Later the asuras came to be understood as demons. This pattern was reversed in Iran, where
ahura came to mean the supreme god and the
daevas became demons. In Hindu mythology, the
asuras and the
devas together sought to obtain
amrita (elixir of immortality) by
churning the milky ocean. Although they had agreed to share the
amrita, strife broke out over its possession, which led to a never-ending conflict.
Zoro has also been likened to an Oni and even called "Green Kaido" at end of Wano which imo is not just a joke, but examples of foreshadowing like Sanji being "Mr Prince" for example. I've joked Zoro is related to Kaido, maybe has some Oni DNA in his genetics somehow and thats why he's so tanky/durable and relentless too?
Someone will make more sense of this and think of better stuff than I can too though lol.