Overall I like the concept, though that's a lot of defensive skills for a DPS job. I do like the idea of a job that builds around something besides stacking Crit.

I'd maybe make the stacks spendable on the chain skills instead of just unlocking them. Then you're building up the stacks and spending them, instead of just hitting 100% during a boss fight and leaving it there. It would also help to differentiate it from MNK. (This might have been your intent, it's not clear.)

You could also work in FFXII skill name references like "Shades of Black" and "Inquisitor".