The only thing I know of the connection is that the zodiac is a big theme.

So are Cid, Biggs and wedge but I think Gilgamesh is more of a God just based of the fact that the Gilgamesh based on Mesopotamia scrolls says he's a god/king. I base this off of Odin riding slepinir in his summon forms, leviathan being a "guardian" and so on. This is just my half assed theory though and I Know I have more work to do to make it more believable.

Square took a lot from ancient mythologies (japanese artists seem to have a thing for ancient myths), and yes, you could definitely see Gilgamesh as a god, within the FF multiverse.
A goofy, silly, minor god, yet still, an immortal being.

What about Gilgamesh?

He's more of a running gag, in for shit and giggles, not really much of a plot element, at least in the latter games.

Besides, he is stated to be an extra-dimensional being, every time he dies he goes adrift the multiverse, and every time he ends up in a new reality he tries to get the best sword in existence.

And fails.
Miserably and hilariously so.

So are Cid, Biggs and wedge but I think Gilgamesh is more of a God just based of the fact that the Gilgamesh based on Mesopotamia scrolls says he's a god/king. I base this off of Odin riding slepinir in his summon forms, leviathan being a "guardian" and so on. This is just my half assed theory though and I Know I have more work to do to make it more believable.

Square took a lot from ancient mythologies (japanese artists seem to have a thing for ancient myths), and yes, you could definitely see Gilgamesh as a god, within the FF multiverse.
A goofy, silly, minor god, yet still, an immortal being.

i grew up with that game back before i even had a grasp of reality it was flashy and cool