Blackjack is the ultimate duel colosseum scenario, you unlock it after beating inward chaos, , the final Destiny board story, which is unlocked after beating each player destiny board and the distant heroes (shantotto's and gabranth's), and purchase it at the PP shop for 2000 pp.
I'm right in the middle of completing the genji set, for the ultimate EX build :P with stefl1504 my EX build worked well, but i lacked the full absorption power of the genji set, which would allow me to be always in EX mode xD.
My main Cloud is at level 100 and my Zidane is at level 95 now, after completing the Genji Set i'm going to start hunting for the excalibur II, which is the ultimate weapon for an Ex Build, it gives you 100% experience points, so with the ability Exp ---> EX equipped, you can see how quickly I would gather EX in a battle :P
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"
