Except for equipment sets, forget that, Oraen can keep that: Alluvion Skirmish:

Vana'diel Areas Weather Time Calendar. The flip side is that physical AoE moves absorbed by utsusemi shadows will remove occultation without mitigating damage.

Obviously, I didn't include spells that were in the base set over again. I just can't say how much this neck helps when you need that extra defense. Grants a TP bonus to Chain Affinity.