New Job Concept: Riskbreaker

[Seraphor]

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".

I think without the defensive skills it'd be a paper tiger far worse than DRG or BLM because it actually loses defense, healers would hate it. The skill would be in balancing your offensive skills with the defenses you need to survive.
If you don't need the defensive skills, you can turn them into party utility.
And it's really only 3 defensive skills. One of them is more resource management with a passive defense boost, or rather it negates your defense penalty. Another is a toggle that allows you to use the other three on party members while changing the resource/penalty for it.
Of the three actual defensive skills, one is a return damage so it's a DPS boost, the other two are minor single target mitigation, one of them is basically a non-tank Awareness, while the other is something DRG already has anyway.

You don't just get the stacks and sit on them, they each have a 10s duration, which means if you're not constantly attacking, you will lose the stacks quickly. Basically, if you stop attacking each stack will drop off every 2.5s, or whatever your GCD. It's more engaging than MNK in this sense, you can't just stop for a few seconds, unless you use the Sirocco skill.

The defensive skills already spend stacks, i think any more would be overkill, as you'd never actually get to 5 stacks long enough to use that higher crit rate.
Plus then there'd be nothing to differentiate risk stacks and momentum. They're similar and interact, but they're still meant to be two different resources used in different ways, one offensive, one utility/defensive.

I did try to think of FFXII terms I could use, but Inquisitor would basically be Soul Sap (Vagrant Story's name is actually Siphon Soul but that's too close to a DRK ability) and I'm not sure where Shades of Black would really fit, closes would be the Pain skills but it's not really black magic.