Originally Posted by
Nume
So, we kept hearing about these burn sul strats preventing him from empowering, but for whatever reason We always had trouble either getting sul down enough or breaking empowers in time (if we had too much on him) so if we did break empowers we'd have to deal with him empowering and the sand adds always gave us fits (not sure exactly why). The strategy we found that made it so much easier was kind of the opposite of most. We didn't touch sul at all other than interrupting, and made sure to hit kazrajin and high priestess a little bit (just enough so their health would be lower than sul's). By doing this, we caused sul to empower 2nd (the highest health boss who hasn't empowered int he current cycle is always the one to empower). With him 2nd, there were almost no sand adds, and his empowerment was super easy to deal with. After that we went to a more "normal" strat of sticking a melee on sul full time and cleaving/double dotting him while killing empowered trolls, and easily killed him before the 8th empower (which is the next time he'd empower since he was lowest health the 2nd time through) which made the fight super easy.
TL;DR: Don't touch sul til after he empowers right after frost king, then burn him like normal while handling the fight normally if you don't have the dps to kill him before he empowers with the burn strat.