My theory for Sigmascape

[Melichoir]

Personally, Ive been under the impression that Omega weapon will be a "Best of the Classic FF" bosses. So that there isnt exactly going to be a huge rhyme or reason for the lettering (Delta, Sigma, ???). I mean there probably IS a reason for the Greek Lettering, but its probably more an abstraction or a wink-wink-nudge-nudge than some deep philosophical meaning.

That being said, youre more likely to see bosses from Final Fantasies that were note worthy. So my prediction is youre more likely to see bosses from...

FFVII
FFVI
FFVIII
FFX

Bosses from these games would make more sense, since theyre more iconic and widely known from the FF games, and FFXI, FFXII, FFXIII are to 'recent' as titles, and the earliest FFs were already semi represented with Deltascape.

Of course, they could also be operating by systems. So Deltascape was FFV on the SNES, Sigma could be a Playstation Title, and the last of the Omega could be a PS2 Title.

OR They couldve named it Delta because V and the Delta symbol look similar, so Sigma could be FFIII cause you know, similar looking.

[Settiesama]

So that there isnt exactly going to be a huge rhyme or reason for the lettering (Delta, Sigma, ???). I mean there probably IS a reason for the Greek Lettering, but its probably more an abstraction or a wink-wink-nudge-nudge than some deep philosophical meaning.

They're named this way because of Omega himself, named after a Greek Letter

[Melichoir]

They're named this way because of Omega himself, named after a Greek Letter

Well I got that, but why particularly Delta and Sigma, and not lets say Phi, Theta, Kappa, Alpha or other Greek letterings?

[Nestama]

so Sigma could be FFIII cause you know, similar looking.

Problem with that is the Crystal Tower raid has most of the noteworthy bosses of FFIII in it.