The Golden Scourge(King Ghidorah reader x Highschool DxD)

Before the Great War, the devils, angels and fallen angels were fighting against a powerful entity. It arrived on their world, claiming it was the Apocalypse. It then proceeded to slaughter anything that crossed it. But then it met the Heavenly Dragons.(They're female). He was forced back the two, and for the first time is very long lifetime, Ghidorah fell in love.

He was absolutely enamored by the two. He promised to cease his slaughter if they stayed by his side. When they replied with yes, as they had also fallen in love with the Golden Terror, the living apocalypse was overjoyed. They were happy for a long time. Until the Great War came.

And the two tried to kill each other. Ophis, the little conniving lizard had used her way with words that the other was trying to take Ghidorah away from them. Their battle for Gods attention, who sealed them away. Just as Ghidorah had arrived to stop them. Upon seeing his lovers dissipate, his hellish rage and fury turned towards the entities that caused. First, the one in front of him right now. Next, Ophis.

Now you know who killed God.

After Gods death, Ghidorah seemingly returned to the stars.

He had actually gone into hibernation on the moon.