One Combat that is Risking the Earth (Chikyuu wo Kakete Ikki Uchi- 地球を賭けた一騎打ち) - S1.E30

Prince Heinell conducted a Boazanian ritual of drinking a golden eagle's blood and taking an oath to fight until death. Kazarin wanted to protect Prince Heinell by taking initiative to trap and kill Kenichi first. She wrote a letter saying she knew where Dr. Gou was and asked to meet him. Kazarin disguised as a nun named Jane and meet Kenichi at a church full of booby traps. She failed to kill Kenichi and later Prince Heinell came to save Kazarin and had a duel with Kenichi.