Gintama - Season 4 Episode 49 That’s How I Wish to Be, Beautiful and Strong

Consumed by negative emotions, Douman is transformed into a giant demon. He now possesses within his body Antenmaru, a demon sealed away over a millennium ago by the desperate efforts of the Ketsuno and Shirino clans. As Seimei is about to be killed by Antenmaru, Gintoki stands before him with his aura-charged wooden sword. Gintoki charges his sword with everybody's energy including Douman's in order to overwhelm Antenmaru and bring a sunny day. After Antenmaru is destroyed, Gintoki leaves so that Ketsuno Ana will not know about the fight. However, he requests Gedomaru to make Ketsuno Ana to give him her autograph. Douman appears alive and ends up having a childish fight against Seimei. As Odd Jobs leave, Ketsuno Ana expresses her thanks to Gintoki in her weather forecast.