Humanity had left earth behind, and travelled into the stars. Spaceships carried millions of passengers to other planets across the galaxy. Humanity had discovered almost unbreakable material in the core of every planet, named Eranium, after the planet they first discovered it on. The United-Planets-Alliance (UPA), commissioned ships nicknamed Planet Crushers, designed to create large, circular holes in planets that were not able to be inhabited by humans, and collect the ore from the core. Humanity was successful, until it made contact with an alien race, known as the Federation. The Federation was made up of aliens called Ciphers, who were like humans, but had green shaded skin, and whatnot. The two sides declared war on one another, and at first humanity was winning. However, the Federation managed to regain territory, and invent crushers of their own. Now, everything was at stake, as each side used their aircraft to destroy planets. Now the galaxy's fate is up to Some soldiers.
What if Rimuru was instead reborn as a primordial demon; the strongest in combat and intelligence.
He reincarnated just before Star king dragon Veldanava created the omniverse; it was nothing but a void, his soul being exposed just a little to turn null made his soul undergo a change. Making him an individual with a high evolutionary potential