Need advice on killing doryani

I have tried and tried but I can't get out of the large slam he does. Everything I have seen just says run and dodge out at the last moment but is that all there is? No matter how much I try and dodge away he appears to travel at the same rate so I am still in his range.

So what do I do?
1) keep going until I find some speed boosts
2) increase my armor/health to x so I survive it
3) learn about some trick I didn't know
4) just keep practicing on how to dodge at the right moment while still inside the aoe
5) increase dmg until he doesn't live to get to that stage
6) none of the above
7) all of the above

This is another one of those crap tuned boss fights. If the RNG gods have not gifted you with speed increase gear.... you're kinda f'd. Plain and simple. Any game that requires RNG to beat a boss is a HORRIBLE design.

This boss is truly atrocious. [Removed by Support] a bullshit one-shot mechanic that is dependent on having the abysmal loot RNG bless you with move speed on your boots. This is one of the worst designed boss fights I've seen in my life.

I finally survived it after leveling again and quickly potted and finished the fight. Another point to my arguement that act bosses are too hard; I started maps and I don't even have to help my minions on the low maps.

There is no way that the gate for the next step in progress should be that much harder than the next section.

For the slam attacks, I think more life would help. My witch has 1200 life + 1000 mana (with Mind over Matter) as an extra layer of defense, so the slam attacks are not a problem, but I kept getting 1-shot with the chaotic laser attacks, then I tried to boost my lightning resistance (~25%) + lightning res charm and the boss turned easy for me.