Current State of End-Game Contents - A Blog Post from A Japanese Player

[Gormogon]

You could resize your focus target bar to be massive and stick it right in the middle of your screen if you fail to realize there's a bar casting that says twister, that shows it's exact cast time, that's not an imperfect indicator it's called a lack of awareness.

Getting people to do that during the middle of a fight is pointless.

If I was a tank I'd go in with a macro that indicates twisters are being casted. There's many alternatives but a surefire way for a fight like this is VoIP since we don't have access to DBM in FFXIV.