We Live in a Universe next to an infinity of others. We can't comprehend, let alone see these other universes, but sometimes universes can connect with each other. One of these universes in our multiverse is the Dream Universe. The location of the Dream Universe surpasses any possible conventional frame of thinking.
The Dream Universe is full of creatures that call themselves 'Dream Watchers'. The only way creatures from the Dream Universe can show themselves to earthlings is through our dreams, which is another universe on its own. However they cannot travel to the earthlings physical universe.
Like our world, the Dream Universe has lands that the Dream Watchers change themselves. The worlds they build for themselves are varied by their personalities.
The Dream Universe was not always like this, as the portal between their Universe and our dreams hasn't always been open. Before then their world was dull and desolate. Only when the Dream Watchers could see our world through our dreams did their world grow in creativity. But with creativity comes conflicts. Earthling dreams are rarely accurate to what life on earth is truly like, most dreams are extremely abstract. Over time Dream Watchers acquired personalities, opinions and tastes. Some of which conflicted with each other. Naturally certain Dream Watchers made friendships and some even groups. The Dream Universe had a growing culture that was inspired from earthlings.
But one Dream Watcher in particular didn't want the Dream Universe to change. This one was named Yame among the others, who saw only nightmares from earthling dreams. He divided the Dream Watchers into two groups, Nightmare and Lucid. The rest of the inhabitants of the Dream Universe are in uncharted territory by Lucid, Nightmare and the other Dream Watchers surrounding the local area.
The goal of the Lucid Dreamers is to educate those in the Dream Universe about earthling life. Lucid focuses on the good that learning from our universe can do, Especially making friends and family. They also study building on to lands. This includes adding on to the earth, plants, atmosphere and even fauna of the Dream Universe. They also make buildings and other structures for comfort. While Nightmare focuses on turning everything back to the way it was before, un-creative, fighting for more territory.
Last there are the neutral Dream Watchers who are indifferent to the entire conflict of the two clans. Some lean more towards 'the wold way' and some have grown accustom to how life is lived on earth.
Both Lucid and Nightmare in this point in time are growing in numbers. They're both learning about our universe and adapting as we do. Though their knowledge and technology is very limited, over time they work to gain more territory. The Nightmare clan is against the impact our universe has on theirs. But still they send students to learn about our universe and the dimensional portal that lead them to it in hopes to someday destroy the portal and bring the Dream Universe back to the way it was.