Jiren is currently the most powerful character in Dragon Ball Super and fans have been eager to learn more about the mysterious fighter. The show revealed that the Universe 11 fighter isn't just strong, but that he can take on a God of Destruction and win. Fans have been wondering about the character's motivations and it turns out that they can find out more about him via the official manga.
In the manga of Dragon Ball Super, it is revealed that the character is more peaceful than he lets on, not even wanting to participate in the Tournament of Power. The manga is still pretty far from the anime, so why Jiren eventually participates in the tournament isn't revealed yet. Still, this shows why he isn't a God of Destruction like Beerus or Champa; he doesn't want to be one.
The Super anime hasn't gone into much detail about Jiren's backstory, mostly focusing on his fighting prowess. He's taken on Kale in her Broly-like Super Saiyan form and Hit, the assassin that fought Son Goku at the end of the Universe 6 arc. Jiren also had no problems taking on Goku before, though the Saiyan's recent Ultra Instinct state may prove to be the warrior's undoing.
Fans can currently stream Dragon Ball Super on Crunchyroll, though only time will tell if we see his backstory in the anime.