"Vegeta: Kakarot backed him into a corner, and it seems the prospect of him losing made him relive all his trauma from his past.
In this state, Jiren gains a substantial increase in muscle mass and definition causing veins around his body to bulge out, and an aura which has a sparkling crimson color and a pattern consisting of rippling, fire-like energy similar to Goku's Perfected Ultra Instinct with red sparkling trails of particles.
Usage and Power
In the anime, Jiren achieved this state when the fear of losing made him relive all the trauma from his past, allowing him to break through his previous limitations in order to battle Perfected Ultra Instinct Goku. Jiren unleashed a newfound power so intense, the very release of it caused the top portion of his Pride Trooper uniform to be blasted off, and set the tournament ring ablaze with fiery ki. The release of his unthinkably colossal ki was unbelievably intense, that the Null Realm was violently shaking as his fiery ki was spilling out and scorching everything around him in intense heat akin to an active volcano.
In this state, Jiren was capable of going toe-to-toe with Ultra Instinct Goku, gaining enough power to bypass the instantaneous defense impulse of Ultra Instinct and even initially overwhelming Goku in raw power. Even when Goku stood up to fight even after blasted down by a strengthened Power Impact, Jiren was still able to compete against Goku, although he was eventually overwhelmed, due to Goku becoming more powerful from his friends' faith in him. While he was still able to fend off Goku after Goku got angry, his newfound strength soon proved to be outclassed when he was savagely attacked by Goku, after he attacked his friends in the stands.
When he was greatly wounded by Android 17 in the waning moments of the tournament and nearly submitted, Jiren received words of encouragement from Top, allowing him to overcome the trauma of his past and regain his hidden power as result. However, even then, his strength was still overpowered by the combined assault of Goku and Frieza, whom defeated him with the very last of their power.
"I have no limits!!!"
In the manga, the exhausted Jiren achieved this state in response to being overwhelmed by Goku and Vegeta's teamwork, boasting that he had no limits and powering up, to Vegeta's shock. The boost in power allowed the exhausted Jiren to go from losing to Goku and Vegeta's assault to being able to charge through their combined Kamehameha-Gamma Burst Flash (the power of which altered the entire Null Realm) and knock Vegeta off stage, however he in turn was knocked off stage by Golden Frieza when he was distracted.
Video Game Appearances
In Caddass and Dokkan Battle, this state is referred to as "Full Power".
In Dokkan Battle Jiren in this form appears as both a playable unit and a non-playable boss.
In Dragon Ball Heroes, this state was named "Super Full Power".