I didn’t mind Sylvarria and her little cavern that much, honestly. Then again, I didn’t mind Sentinel either once I learned to keep him away from his crystals.
She’s probably straightforward for tanky toons with the right resists. But for squishy types … nowhere to run to baby … nowhere to hide!
Fortunately it got tuned down from what it was when Ashes of Malmouth launched. More golem’s used to spawn and at shorter intervals.
Basic tips - use venomguard ointment, and make sure your pierce and bleed resistances are maxed. You also should have sufficient DPS and AoE stuff to deal with the spawns, but if you’ve got high life-steal, healing or tankiness, focusing on Sylvarria and killing her also takes her golems out.
I managed her after a few attempts in Ultimate. The main issue I have with that arena is the fact that moving around in it is so risky. Five or Six(?) plants side-swipping you for 20% of health on top of between 3-6 Shamblers(?) who come straight at you… Yeah, pain in the neck.
I chose one spot to stand/retreat to and just took out all but 1/2 Shamblers and then went straight at her until she spawned greater than 2 adds. I could comfortably ignore two adds but absolutely had to pay attention to 3-6 of them. As a Warlock the poison/acid wasn’t the issue it was my squishy build being molested by her brutes.