I like the look and idea behind this gear, but what legitimate use does it have?
My only thought is for a gunslinger who wants Elemental defense instead of Piercing, and would go with the Shadowsun anyway... which I might end up doing, but even then it seems weak.
Chaos is probably the worst 5* gear set in the game. Its only use is as a costume or a Very Hard Mode. :V
The damage bonuses are really negligible. Unlike other gear, for example it can be worth taking Skolver or Mad Bomber into FSC for the bonuses, Chaos really doesn't help that much compared to the massive weakness to everything.