The strategy for Skolas has changed since the new update. Now what happens is that you need to do mob management up until you break his chains. After that you have a strict "juggle the essence" once the time hits 10 seconds. During that time you move from corner to corner of the map to avoid getting wiped out by mobs and Skolas. (You're also slaying mobs as you go) Once the mines spawn you make sure to grab the essence off whoever may have it at the time so that you don't have to be screaming for someone to take it mid route to the dismantle. After you're through the two rounds of mines you can relax juggle the essence and finish off Skolas. Average play time from start to finish of Skolas now is 1-2hours depending on your team.