A Record of a Marriage Between Heaven and Hell

In the 4083rd year of the Fifth Era of the Galactic Empire, the ten-thousandth year of humanity's war against the evil spirits of the subspace. The newly inducted Star Guards swore allegiance to the Emperor of the Human Empire. The Emperor blessed them: May you die in battle, and may your souls go to the Great Throne. Upon the Great Throne, the Holy Lord of Heaven, the merciful Flame Archangel Saint Michael, will receive your pure white soul and cloak you in glory. The Holy Lord of Heaven, Michael, has been in high spirits lately. Beyond the Ninth Heaven, a vast, pitch-black fleet lies in wait. Satan is preparing to launch a counterattack against Heaven. At last, he has an excuse to take the Holy Flame Sword back from its shrine in the Human Empire! Everyone knows that Satan, the lord of Hell, was thrown down from Heaven, so they all assumed he would immediately raise his arms and cry out, charge up to the Ninth Heaven, fight his way from east to west and back from south to north, avenge his humiliation, and leave rivers of blood and piles of corpses in his wake! But he didn't. Satan had spent thirty thousand years diligently building up Hell. Though storming Heaven might have sounded more thrilling, the demons' standard of living had genuinely improved. Just as everyone thought Satan would keep devoting himself to transforming Hell... He decided to launch a counterattack against Heaven. The evil spirits of the subspace were locked in a fierce battle with humanity when they turned around and thought, Huh? Why is the Holy Lord of Heaven's angel army here? So they ran in the opposite direction, only to find the hellish demon army waiting there. What happened to Heaven and Hell being about to go to war? Who exactly are they fighting? "Where my sword points, all evil spirits shall be silenced!" "If you are the sacred flame, then I will be the kindling. I want to watch you burn everything to ash." Couple: Lucifer x Michael [Reading Guide] 1. This is my own take on mythology. Aside from the characters' names, it's basically all original, which is why it's listed in the Original Fiction section. 2. These aren't traditional angels and demons. The main setting is science fiction, and Heaven and Hell will have technological creations too. 3. I haven't used any of the widely popular fanon settings, so please don't come in with preconceived notions. 4. May the Holy Lord bless us never to lose sleep! Theme: Protect the world!