S4E20 : And into the Legend...

At last, Gintoki and his friends confront the Great Archfiend. While the Leukocyte King can’t lay a finger on the Great Archfiend who has taken Tama’s form, Gintoki attacks without giving a damn. Angered by his reckless impudence, the Leukocyte King turns on Gintoki. The Great Archfiend then takes the form of the Leukocyte King’s father. But this time Shinpachi and Kagura attack him, and they succeed in kicking him off the throne. The Odd Jobs trio takes this chance to finish the Great Archfiend off, but...