One key element is the near - extinction of his race. This event had a profound impact on him and motivated his pursuit of strength. Another is his membership in the Pride Troopers, which shaped his fighting style and his sense of justice. Also, the destruction he witnessed in his youth is an important part of his back story.
Jiren is a powerful warrior from Universe 11 in Dragon Ball Super. His back story is centered around his quest for justice and strength. He comes from a race that was nearly wiped out. This tragic event in his past made him determined to become stronger so that he could protect what was left. He trained rigorously under the Pride Troopers and became one of the strongest beings in the multiverse. His sense of justice is unwavering, and he believes that true strength should be used to uphold order and protect the innocent.
In a crossover with One Piece, Luffy could be an ally. Luffy is known for his open - mindedness and ability to befriend almost anyone. He would see Broly's power and might try to get him to join his crew or at least fight alongside him against common enemies. They could have some really fun interactions, like Luffy trying to make Broly laugh or share his love for food with him.
In a crossover with the Naruto universe, Naruto himself could be an ally. Naruto has a way of seeing the good in people, and he might try to reach out to Broly and convince him to use his power for good. His ability to befriend and understand others could be key.