There is 2 things in Logon fight that can be exploited … I don&t know if someone already mention it
First – In first part of the fight just before fight start you can jump outside his area . If you are ranged character you can safely hit him from outside his tentacles and he will not reach you … I did that yesterday … that work for first part only , next 2 parts he teleports you down and back in .
Second - it is possible to stand in the far left corner there is a spot where he cant hit you with his breath or smash you . Only lightning explosion can hit you there . So if you able to tank that you are safe there , you can stand there without moving and hit him . That also works only for ranged off course …
I dint think those two situations are intended to work that way