Sigmascape V4.0
Strategy
First phase, just avoid the AOEs and shoot him. Eventually the boss will say something along the lines of “you think you learned my tells?” and Nero will holler at you, and the AOEs after that will have giant question marks in them; for this bit, you need to stand in the AOEs. There will also be some fire markers, take them away from the group.
Throughout the next phases, the boss will occasionally cast a teleport to somewhere by the edge of the arena. When he’s done teleporting, he will either instantly do a massive column knockback in front of him OR do a cast for a shorter AOE knockback all around him, so what you want to do is position yourself off to the side or back of his teleport circle so you’re safe if he does the column AOE, and then move in front of him if he’s doing that cast for the circular one. He also does occasional smaller knockbacks, so try to tank him towards the middle of the arena and if you’re ranged, don’t hang out near the edge. Also, the AOEs from the first phase will continue to go off through the statue phases, watch for the question marks to know if you need to stand in them (question mark AOEs) or avoid them (plain AOEs). There are also stack markers sometimes, because of course there are.
Hell Phase
A gigantic demon statue will spawn outside the arena. When the boss casts Graven Image, the statue will cast a pair of column AOEs towards the group and also a glowy green orb will spawn at one side of the arena or other and do a massive knockback a la Shinryu's waterspout. Watch closely for where the orb spawns so you can move towards it in time.
Purgatory phase
After the demon statue does a its thing a few times, the statue will shift and will occasionally cast an AOE that covers half the arena, check the statue for a glowing orb to see which side will be affected.
Heaven phase
The statue (this time a twisted parody of Michelangelo's Pietá) will shift one final time, and a giant “don’t look” eye will spawn on it from time to time; if the eye is yellow and has a question mark on it, face it; if it’s purple, look away. The eyes come thick and fast, so keep an eye out (all puns intended).
Loot
Lore
The looming face of the Sigmascape, "Kefka" will be your final opponent in this test world. Analysis of his data reveals that, despite his comical appearance, this cackling jester once rose to godhood and cast his entire planet into ruin. His is a power not to be underestimated. Nero has also alerted you to the villain's propensity for trickery, and promised to watch for deadly feints through his enhanced monitor. You can only hope that his warnings come in time...