Cover?

[Zoomie]

You should use it when you know someone is not gonna live through a certain unavoidable aoe like hellfire/aerial blast/tumult/earthen fury. I was in a pug for garuda NM yesterday as a SCH and a BLM died twice not having enough HP for aerial blast so I told the PLD to use it and he's like I never use it. What? It's there for you to use it. Play smart.

Cover is for physical damage only. I'm 99% sure it won't work on aerial blast.

The only times I've used it are for an added layer or protection while a melee is Limit breaking or for fun. I tend to tank Hydra A LOT (5 times yesterday) because people have issues with it or just need it for their relic. I enjoy using cover on the other tank and poping hallowed to eat a few triumverates. Imho it needs to have a longer range and absorb both phys and magic damage. It would become much more useful.