Guild Wars 2

I have spent several hours with a toon parked at the spot of the last vines. I have helped in each event that is supposed to turn on the pylon(s) yet the vines never clear. I believe that the meta never activates these pylons anymore as they are not needed.

How do I get this last mask now?

I helped a guildie with this mask just last week. It’s still accessed by doing one of the event chains from the South.

Once the South Waypoint is clear, you follow the Exalted who is just east of the waypoint. You then do a series of events including I think it is 3 where you take down what appear to be some kind of egg sac. After that, the exalted will go to the vines and once you have defended him, the vines drop and he will activate the pylon, leaving the area open for you to collect the mask.