Before Rimuru Tempest reincarnated in the Great Forest of Jura, there was another who was brought to this world after suffering a similar fate. However, he came into this new world not as a human or a slime, but something much more terrifying in the form of a catastrophe level threat; a legendary True Dragon. Disclaimer: I don't own That Time I got Reincarnated as a Slime or any of its characters, just this story, and my oc. A/N: This story will follow the manga of That Time I got Reincarnated as a Slime, but with a few changes to it thus making it an AU.