Living Dead doesn't really make sense from a Final Fantasy lore perspective, either. Vengeance, Justice, and Tenacity are themes, sure, but Undeath isn't. Dark Knights are not Death Knights, and if we were, we'd probably have the self-healing to support the ability (WAR can, we can't). Someone was staring a little too hard at Warcraft for ideas when they tried to rip off Purgatory.



The best ability designs are simple and intuitive. In the case of invulns, they also have to be dps neutral (MP draining or generating concepts don't work because you either avoid the ability or try to proc it on recast). Living Dead is just too convoluted. It needs to be scrapped and redesigned from the ground up.

I think there is a broader problem with invulns, in that with 4+ uses per fight between two tanks, there's a ton of damage that you can simply trivialise, so much so that you don't really have to ration out the rest of your defensive kit.

If you want the healing and mitigation checks in fights to have more challenge to them, you need to put an upper limit on both invuln and raise uses per fight, shared across your entire team.