The Clockwork Empire

Crashing onto the planet from an unknown origin in space, the Adamantine Clockwork Horror, a metal monster shaped like a strange beetle, immediately started creating more Clockwork Horrors. Their purpose was to kill everyone on the planet and strip mine everything on it in order to create a new army of Clockwork Horrors. Once their goal was found out, the world created the Fence. The Fence is a series of large towers imbued with powerful magic, that cuts off the Clockwork Empire from expanding. The towers of the Fence rise above mountains and above clouds, and go deep into the earth. The only thing taller than the Fence is the Spire. For centuries the Clockwork Horrors have been unable to get past or around the Fence. After the Xanathos Event, the Fence is still functional but the magic has changed and those once responsible for the maintenance of the Fence are not sure how it works any more.