Sigmascape V3.0
Guardian
MrHappy's video for this fight should give a decent idea of the fight. It is featured in the top-right of this page.
A large part of the fight and positionals are summarised by two macros. Default positions can be used as listed below and with PUGs communication gets a lot easier using them as well, as it should be what most of PF is doing anyway.
The macros are given here as well, but they do not show correctly in browsers. If you copy/paste them into FFXIV, they will show correctly.
Positions
H1 Tymo D1 Seuny R3 Gust
H2 Marielle D2 Shiroe R4 Superazraq
The Four Programs
Certain programs will be loaded over the course of the fight, shown by the screens at north, which telegraph different mechanics happening. The video guide provides an explanation that is more detailed. Loaded programs should normally be called out well in advance.
The most important mechanics, position-wise, are in the macro and use the default positions listed above.
Virus
Positions the same as before, with Tanks and Healers positioning as the mechanic demands.
All players in the corners should move slightly apart after being pulled to not clip their explosions.
Acknowledgements
Macros adapted from macros by Tymo Aimali from Moogle.
Timeline by Syldris Lia.