I just did "The Insatiable" Achievement over the last few days and did 5 relics, I did Titan (Hard) as WHM, SCH, SMN, BLM, BRD. Obviously I have already done it ages ago as the previous melee/tank jobs. Out of those 5 jobs I think I died to that attack maybe once, on WHM, by reacting slowly. The only times I got hit by that attack was when I was trying to finish a cast instead of dodging. I rarely if ever look at the cast bar and move when the AOE pops up. I don't see any issue with that attack at all other than if you have a bad connection or are just slow at dodging.