Guild Wars 2

September 2014.
Part1:
Magister Tassi has appeared, his instruments are picking up signals from the underworld and have lead him to godslost swamp, candy corn elementals have appeared early and are starting to invade through portals, the priory and vigil have gathered to contain the threats that have appeared while Tassi conducts research, convinced that the thorn family have stirred and have secret plans.
Part 2:
one time event!
Power has amased in the center of the swamp, Portals are appearing more frequently and the behemoth has been absent for a while, but this time he appears and is stronger than ever, Tassi has created an asura gate to open portals to the underworld for a short time within the old structure of the aetherblades west of lions arch, and has been placed under heavy guard, this gate has been tuned to the same frequency as the behemoth’s large portal, but something goes wrong and the behemoth appears where the forces of tyria must amass to conquer the beast.

October 2014:
Part 1:
with the beast now slain lions arch prepares for the upcoming halloween season, Tassi can be found repairing his gate, when unexpectedly skelentons appear, and forces of chaos, teams are sent through the gate for recon and on the other side one of grenth reapers awaits, explaining how long its been since its seen a soul from the living world. the team must explore when now lies of the underworld.
Part 2:
Theres a disturbance within the ruins of the underworld, mad king thorn can be seen wandering but this is not the only threat the lies here, theres tales of an ancient evil hidden and waiting, chaos is becoming unmanageable for the king and he requires help from citizens of tyria as the final Seal on Dhuums chains is about to break.
Part 3: (and final)
Dungeon instance.
Dhuums seal is broken and he has arisen, The reapers have once again gathered but this time they have no intention to imprison him again, Tassi and the mad king have formulated a plan to defeat this evil once and for all, and need the teamwork and courage of tyria to Successfully complete this task.

id like constructive feedback for this please =]

One time events have proven to be disastrous in the past so I doubt Anet will ever do one again

maybe, but i think this story arc could bring players together because it has something connecting back to gw1