Dr. Xeno is introduced as a brilliant but bitter scientist who once helped Senku as a child by providing rocket-building instructions when others refused. He is now an antagonist with advanced scientific powers, opposing Senku and the Kingdom of Science. Their relationship is complex, marked by past indirect contact and current ideological and strategic conflict, setting up a tense standoff in episode 5.

Taiju is made to impersonate the science leader by Gen's deception to protect Senku. Xeno believes Taiju is the leader, making him a better target because Taiju is physically formidable and can defend himself, unlike Senku who is less capable in combat. This ruse is intended to shield Senku from direct attack during the escalating conflict.

Senku and his team focus on powering up their ship, the Perseus, and preparing for the impending confrontation with Xeno's forces. They engage in tense negotiations and strategic dialogues, weighing their scientific resources and planning how to counter Xeno's advanced technology, which was created with limited resources but is highly effective.

Episode 5 gives Taiju a new role as the temporary science leader, dubbed 'Dr. Taiju,' which is a departure from his usual role as a tough manual laborer and comic relief. This new responsibility challenges him to act as a proxy for Senku, showing a nervous but enthusiastic side and adding fresh dynamics to his character during the tense negotiations with Dr. Xeno.

Gen infiltrates the enemy castle as a spy and is interrogated by Dr. Xeno, providing false information that fuels the deception about Taiju's leadership. This interaction is crucial for gathering intelligence and setting the stage for the strategic standoff, highlighting Gen's role in espionage and the psychological aspects of the conflict between the two scientific factions.