The Beyond is the unknown "place" beyond all of existence holding all Monocosms, such as The Barrel. Beyond the Omniverse, beyond The Outside, and beyond The Barrel. What lies beyond could be something completely different than what we call existence.
Within this void, an infinite number of Monocosms can be found. To entities who can only comprehend forms of existence within their own Monocosm, these many alternate Monocosms may appear as a field of shining lights, each light being a separate Monocosm. The -verse containing this great void and all the Monocosms found within it is known as the "Beyond Bubble".
An entity who came to be known simply as The Omniversal Traveler exited the Omniverse to find any existence beyond the immeasurably large void known as The Outside. This led him to discover Beyond and its many shining lights. This was a form of existence completely beyond anything he ever knew even existed, hence he named it 'Beyond'.