Who is psy's older brother in naruto Shippuden?

In "Naruto Shippuden," Psy's older brother is not a character, as Psy does not exist in the Naruto universe. However, if you meant "Sai," his older brother is Shin. Shin was a member of the Foundation and played a significant role in Sai's backstory, particularly in how he shaped Sai's emotions and relationships.