etsuzan manages the team from Big Baser beneath the sea, watching over them and keeping track of their actions kept company by his robot mynah bird Kyutaro. He likewise develops new weaponry and means for combat in order to keep track of Egos' own developments in weaponry and espionage. Most notably, he spearheaded the development of Battle Fever Robo due to Egos' own possibility of the creation of giant robots to assist in combat, only allowing for it to be utilized both when it was completed and after Egos showed it's hand by revealing it's robot to the world.

After an incident where Battle Fever is embarrassed by an Egos Monster by putting other concerns ahead of it, he is forced to show them how they are supposed to act in order to prevent it from happening again. Likewise after the sudden death of Battle Cossack Kensaku Shiraishi and his suit being taken by his friend Makoto Jin, he was the only one to show doubt and anger at what the new team member pulled and showed mistrust in him and his possibility of selling them out to Egos until he proved himself.