The Final showdown against Orcus, a 5e Level 20 one shot

About the adventure

The armies of Orcus swept across the material plane like wild fire, mercilessly destroying entire nations, wiping out whole cultures and reducing them all to nothing more then undead slaves. The initial onslaught was without warning and quite severe, catching even the staunchest defenders unawares. Little time had passed before his armies pushed the various beings of the material plane into despair and potential extinction, they had no choice but to band together, regardless of prior grievances or ignorant racisms they united under one banner led by a Gold Dragon named Yurthriax. 5 years of brutal fighting have since passed, each time the alliance had lost even a single member they were forced to endure Orcus's army growing that much stronger. Through the sheer force of will and what seemed to be miracle of the divines the Alliance was able to push Orcus and his army back into his final strong hold. As joyous as that was in the moment, that was a year ago this monumental shift in power happened and the prolonged siege has proven mostly ineffective. Yurthriax has decided to summon the strongest beings of the realm to fight for the Alliance, to confront Orcus directly, and to hopefully save this world..... To help accomplish that Yurthriax will launch a massive offensive to punch a whole just big enough to get the group inside so they may confront him directly. Once inside, it's all up to you. Can you and your team mates prove to be Orcus's better? Can you save the material plane from the never ending threat of an undead apocalypse? Come join the challenging level 20 one shot and put yourself to the test!