Thanks for the replies.
I finally found out the Amaliorra (scepter, upgraded to Mythic) was doing more dmg, 20-30 ish so I used that instead of the essence interruptor.
However that fight is even more annoying on PS4: hellfire drops famerate to like 0, it made my system crash twice
First time Dorudugan was at 50% health.
The last time Doru was at 35% health, after more than 1 hour of fighting him