Okay, before the Dissidia event ends tomorrow, I decided to run Terra/Cloud once more with Shale-friendly setups, CM-style. This one was a fair deal tougher, but it worked out within a couple resets:
L80 Sephiroth: Mirror of Equity R2, Full Charge R3 (Heroic Stance). Worth noting that I used only four shots of Full Charge here, so running it at R2 is viable. Dark Bargain is also a more damaging, but less safe alternative to Mirror of Equity.
L71 Kefka: Memento Mori R4, Dark Zone R3 (Devotion). R2 Dark Zone is enough to kill Cloud, but having an extra 40k to drop on Terra isn't a bad idea. I wouldn't recommend trying Memento Mori below R2 (ideally, it should be R3, even), you want Kefka to not be dead weight later in the fight.
L80 Leon: Magic Lure R2, Lifesiphon R4 (Dr. Mog's Teachings). This drops Leon's damage considerably (DBB goes from dealing 9999 x3 to 6k x3, roughly), but I found Terra to be a lot more vulnerable to Magic Lure while at high HP than Cloud is to Draw Fire at the same threshold.
L80 Faris: Magic Breakdown R4, Full Break R3 (Battleforged). Same as before. Faris getting to her SB earlier is good.
L80 Eiko: Curaja R5, Protectga R2 (Mako Might). Yeah, Cloud's offense is actually more dangerous due to his Limit Break stat buff, so Protectga it goes. Every time I tried this party with Shellga, he eventually overwhelmed my PCs.
RW: SG/SSII
Same general strategy: open with Emerald Light and Hand of the Emperor, follow with Protectga and Magic Lure, hyperfocus Seph/Kefka/Leon on Cloud, have Faris spread breaks (Cloud first) and try to survive until Spikes is dead. Terra just isn't too scary until she gets low on HP, at which point Holy is her scariest offering, but at least it can be Magic Lure'd. Dunno if Shale cares about the CM at this point, but I think he can make it work.
EDIT: JP will get a FF1 event next! In which we get a non-core Core and M A T O Y A! ybab, TCELES B HSUP.