Some sort of Problem not many have mentioned before:
Avoiding Stuff depends too much on continous actions, as example: runing left, left, left, left untill you are out of a Circle.

If the server sends to the client "AoE is starting, 8 secunds left to react" and the Player on the client have 8 secunds (maybe just 4 depending on lag) to press one single button (example: defence roll) to avoid the impact - it is ok and makes fun. Most playstation games rely on that system, even high speed action games does have this mechanic!

But what with all those different sized AoE-circles? Indeet it is a problem and doesnt feel right, wen pressing one button saves you from everything (sidekick to pld with his special skill). Also seen on Ifrit how easy the fight becomes if you can interrupt a Boss. However, it is easier to design a combat with adding mechanics than to deal with LAG or netcode. If the game supports silence, stun, blind, lets make use of that... Also pressing more different buttons to avoid larger circles is possible - that leads us to classic action games and currently often seen on playstation. I do not like that direction, but if it will fix the problem i will accept it. At end the game have to be playable!