aye the fight is power hungry and i did state u need to burn them all not just him, dont rely on aoe'ing u need to swop between them equally.
Problem with rougad is that u need to balance the dps amongst him and his 2 dopplegangers tabing between them is best, i spend months fighting him and dieing, but what i learnt from the fight after being so over powered is u need to just keep tabing between them and burn them as equal as u can, most of time 1 maybe 2 dots would drop there Health to 50%, the first and second boss (Maxima) are alike due to u having to balance and run the script mechanics but the whole Rougad fight is a regen cycle for the bosses they will keep regening upto 3 or 4 times to full health.
Some nights when i did he would just die after one round another it took 4 regens etc etc. its random and then another time went in started the burn on the 3 of them and boom they died. so a funky script but once u get hang of it u will see it play out, each round can be different