S21E990: Thunder Bagua! Here Comes Kaido’s Son!

Luffy runs into Ulti and Page One, members of the Tobi Roppo from the Animal Kingdom Pirates. Hearing that he aims to become the King of the Pirates, the brother and sister duo become infuriated and turn themselves into massive beasts. When Luffy is driven into a corner, someone wearing a demon mask appears and whisks him away.