That Time I Got Reincarnated As A Slime S01e245... -

It provides a rare look at Veldora's humorous and somewhat "tsundere" personality while he remains sealed.

The episode you are referring to is titled (Japanese: Kanwa: Verudora Nikki ), which is technically Season 1, Episode 24.5 of That Time I Got Reincarnated as a Slime . Episode Overview Title: "Tales: Veldora's Journal". Type: A recap special that concludes the first season. Release Date: March 26, 2019. That Time I Got Reincarnated as a Slime S01E245...

Much of the comedic value comes from Veldora making up illegal rules (like promoting a piece to an "Emperor") because he refuses to lose to Ifrit. It provides a rare look at Veldora's humorous