FFX dark aeons and penance we're easy as cake, quick hit pretty much took care of all the work.
FFXII had some easy super bosses, specially Yiazmat, but Zodiark was everything but easy, since the battle was mostly about luck, and the odds were against you through all the battle. I had the bad luck of him casting Darkja 5 times in a row xD.
But yeah, when it comes to hard super bosses, nothing in the FF lore is harder than Omega and Shinryu in FFV SNES version xD.
Current PC Build
CPU - i7 8700K 3.7 GHz (4.7 GHz turbo) 6 cores OC'd to 5.2 GHz with Watercooling (Hydro Series H110i) | MB - Gigabyte Z370 HD3P ATX | Gigabyte GTX 1080ti Gaming OC BLACK 11G (1657 MHz Boost Core / 11010 MHz Memory) | RAM - Corsair DIMM 32GB DDR4, 2400 MHz | PSU - Corsair CX650M (80+ Bronze) 650W | Audio - Asus Essence STX II 7.1 | Monitor - Samsung U28E590D 4K UHD, Freesync, 1 ms, 60 Hz, 28"
