Ōga

is an elderly man who kidnaps people for his survival experiments.

Personality
Ōga is an eccentric if not deranged old man. Amoral, he is so fascinated by the concept of life and death, of how people are able to escape death, he has no qualms about putting people in peril just to see how they will react and likewise will kill people just as randomly. In his pursuit of researching survival instincts, he is shown to be very elaborate and methodical in his experiments.

Appearance
Ōga is a short, elderly man of heavily wrinkled, light complexion. He has a wide smile with several missing upper teeth, pupilless green eyes, scraggy white hair reaching his lower back with a long white beard. He wears brown cloths and a red cap with a yellow tongue and white wings on the side.

Abilities
Ōga is a skilled puppeteer, able to manipulate one disguised as himself from a far. He can use the Yin Release to project himself in front of people. He also is skilled in fūinjutsu and space–time ninjutsu, having set up several scrolls to warp people to new locations.

Labyrinth Game Arc
When several passengers on a Thunder Train wake up secluded in a room, Ōga introduced himself through a puppet of himself, claiming that they survived an accident and were exposed to a toxic gas. Ōga believed they had a subconscious ability to avoid death, and wished to test it. When one of the captives drew a death card, he killed them, stabbing them though their head with a puppet. Boruto attacked the puppet with Wind Release. Having made clear how serious his tests were, the first of five experiments began when a Kusa-nin angrily knocked over one of the scrolls, he accidentally activated the "Collapse" test, sending everyone to new location atop of a floor that hovered over a large chasm. Ōga explained that sections of the floor would quickly crumble away and they needed to escape to a higher, safe ledge. At the end of it, only 14 captives survived, and he congratulated them, allowing them to return and rest before the next test.