Kjófu mamuši otoko, Saitó Dósan! (S02E20)

Saito Dosan was mean enough to be considered a viper, and that's during an era of ceaseless warfare between rival feudal daimyo. But for all his ruthlessness, the viper of Mino would still find himself among even more infamous company... when he became the father-in-law of Oda Nobunaga! (Crunchyroll)