Hakugei Conquest Battle (白鯨攻略戦) is the nineteenth episode of the Re:Zero anime.
After he returned from death, Subaru changes his approach, deciding to defeat the White Whale before going after the Witch Cult. Knowing when the White Whale will strike from his previous loop, Subaru offers Crusch's camp an alliance to battle the White Whale in exchange for shared mining rights of magic stones in Roswaal's domain. She agrees when Subaru uses his cell phone to show the time and location of the attack and offers to draw the whale towards himself. Anastasia also agrees to join the campaign, viewing the whale's presence as detrimental to her interests as well. Crusch is impressed by his skill in gathering support, and Wilhelm lets Subaru know that his wife Theresia, the Sword Saint, was killed by the White Whale created by the Witch of Envy and has devoted his life to defeating it.
The next day, before setting off to fight against the White Whale, Subaru and Rem decide to buy an earth dragon from Crusch's domain. He encountered a familiar black dragon, the same earth dragon that Felix and Wilhelm rode to Roswaal's manor. After they bought the earth dragon, Subaru met a large wolf-like demi-human named Ricardo Welkin, captain of Anastasia's mercenary group, the "Fang of Iron".
Subaru and Rem, riding an earth dragon called Patrasche, along with Crusch's army and Anastasia's Fang of Iron, head out to the Flugel tree to wait for the whale to appear. Along the way, he met with two of the Fang of Iron's members: Mimi Pearlbaton, and her brother Hetaro Pearlbaton. Subaru noted that he didn't expect to see her again, but Mimi couldn't recall the time she met Subaru as he had only met her in his previous loop. At the same time, Ricardo approaches to Subaru and Rem as he gives compliments about Subaru's earth dragon. Subaru asks him about the large wolves they're riding, Ricardo answered his question as they are called "Ligers". He also mentioned that he is also prepared for something other than the White Whale. After they had finished their conversation, Ricardo approaches to the other soldiers to ease off their worries before the fight.
That night, the whale appears at the moment Subaru said it would and the battle begins.
- Natsuki Subaru
- Crusch Karsten
- Wilhelm van Astrea
- Russell Fellow
- Anastasia Hoshin
- Ricardo Welkin (debut)
- Mimi Pearlbaton
- Hetaro Pearlbaton (debut)
- Conwood Melahau (debut)
- Subaru's negotiations with Crusch happen at night instead of before dinner like the last time he tried to do so. Most of the dialogue during the negotiations was shortened.
- Russell arrives with Anastasia instead of being there right from the start and in accordance with that most of his dialogue was omitted.
- Subaru and Ferris' conversation was modified to remove any mentions of Fourier Lugnica along with Rem and Wilhelm's appearance and dialogue.
- Subaru and Ricardo's conversation is modified to remove Anastasia and Crusch's appearance and dialogue. And because of that, most of Ricardo's dialog in the conversation, including any mentions and details of the Kobold race, and Ricardo proclaiming himself as a kobold, was omitted and changed to have his conversation with Anastasia off camera. Crusch's part is moved to a separate scene with Subaru.
- Subaru and Ricardo's conversation at the Lifaus Highway was shortened.
- Parts of Subaru and Rem's conversation at Flugel's Tree was omitted, including the part where he reaffirms his love for Emilia and his promise to have Rem as his second wife if Emilia agrees to polygyny.
- Wilhelm's cut part during Subaru and Ferris' conversation was moved to a scene at Flugel's Tree.