There’s a question among fans regarding which character – Broly or Jiren – is Dragon Ball’s strongest villain. Jiren, the strongest warrior in Universe 11, was Goku’s final opponent in Dragon Ball Super and the main antagonist of the Tournament of Power. Though originally depicted as a heroic champion of his universe, Jiren emerged as a true villain toward the end of the saga when the threat of losing caused him to purposely launch a lethal attack on the audience.
Following Goku’s battle with Jiren, he and Vegeta had to team up against a fellow Saiyan in the movie Dragon Ball Super: Broly. The film, which made the Legendary Super Saiyan Dragon Ball canon, saw Frieza orchestrate a fight between his two biggest enemies and Broly, a Saiyan capable of accessing an insane level of power. Having seen what Broly was capable of, Frieza believed that he could use the naïve and innocent Saiyan to get revenge against Goku and Vegeta. Since neither Goku nor Vegeta could beat him alone or even together, the two had to become Super Saiyan Blue Gogeta in order to take him down. Then, at the end of the movie, Broly was finally defeated.
Typically, the Dragon Ball franchise follows a formula where each villain is more powerful than the last. By that logic, Broly should be superior to Jiren, but this is a unique case. Goku had to access Ultra Instinct to beat Jiren but wasn’t able to reach that level again against Broly, so it’s unclear if using that power would have been enough to defeat him. While Dragon Ball Super: Broly offers no clear answer as to which character is stronger, some evidence can be found by comparing some of the fights, which would indicate that Jiren is the strongest.
Perhaps the biggest clues can be found by examining how Frieza fared against both fighters. A severely weakened Jiren admittedly struggled with Frieza at the end of the tournament, but when Jiren was still at full fighting strength, he was able to dispose of Golden Frieza with just one blow. That’s a far cry from Broly’s performance against him. While waiting for Goku and Vegeta to return from practicing their fusion technique, Frieza had to fight Broly for a full hour. He couldn’t hurt him - much less win - but it’s important to note that he was able to remain in the fight for an impressive length of time. He couldn’t hold up that long against Jiren.
Also, Goku said that Broly might be stronger than Beerus, while it was suggested by comments made in Dragon Ball Super that Beerus was greatly eclipsed by Jiren. If that’s true, then Jiren, who has the power of a god, could really be stronger than all other Dragon Ball villains, including the Legendary Super Saiyan himself. If Jiren were to fight Broly, it feels quite plausible that the more experienced and disciplined Universe 11 Pride Trooper would prevail over the more reckless, less-focused Universe 7 Saiyan.