This is a theory on [Oberon],

the combo would be of using the hallowed ground to set a perimeter, use the subsumed ensnare on his 3, and use his 4 on the group of enemies for health orbs, bringing [Equilibrium] to play.

Using [Rolling Guard] when in danger and when an acolyte spawn, giving you enough time to ensnare him and proceed to kill him with the acolyte killer weapon you are using.

the hallowed ground gives you another type of damage as you can reuse to give some damage, but it can be changed to another mod, like prime [Flow] to give more energy to do the full rotation more safely, right now a full rotation will cost you 140 energy, out of the 263 energy bank you have as [Oberon].

additionally, arcane [Fury] is an optional arcane depending on what weapon you use, but energize is necessary, as it gives a good synergy with [Equilibrium].