For years, Gear 5 has been seen as Luffy’s unbeatable form. However, Imu’s arrival at Elbaf completely changed that. After taking critical hits from two legendary swords, Luffy was left too weak to even talk or smile as usual.
But in this dire moment, Eiichiro Oda revealed an impressive new ability of Gear 5: Luffy can consciously command his body to heal itself.
Two legendary swords nearly finish off Gear 5 Luffy

Before Imu appeared at Elbaf, Gear 5 had not truly been defeated in battle since Wano. Luffy faced admirals, turned Kaido into a joke, and wielded Gear 5’s power like a character straight out of a cartoon.
Yet Imu quickly turned the tide. A single burst of Imu’s Conqueror’s Haki knocked down many giant warriors on the battlefield. Scopper Gaban even called it the most overwhelming Haki he had ever felt.

Imu then easily overwhelmed Zoro and Sanji before turning attention to Loki and Luffy. Loki was gravely wounded by Imu and forced to leave the fight, leaving Luffy to face Imu almost alone.
Imu continued using the Omen ability to summon weapons and alter his body, forcing Luffy to explore new ways to use Gear 5, including a strange Genie form. Still, none of these efforts were enough to change the outcome.
At the end of chapter 1188, Imu stabbed Luffy’s chest with the Vohu sword. In chapter 1189, Luffy was pierced again by another legendary sword. For the first time since Wano, Gear 5 was completely powerless.
Just then, Scopper Gaban appeared and blocked the finishing blow aimed at Luffy.
One Piece chapter 1190 reveals astonishing self-healing ability

Chapter 1190 continues with Gaban taking Luffy to safety and candidly discussing the price of becoming Pirate King. Then, Gaban returns to confront Imu directly, unleashing Kamakiri Buppo and Kamudo attacks.
Gaban fights fiercely, but Imu quickly counters and severs Gaban’s arm below the elbow. This detail draws a parallel to Shanks sacrificing his arm to save Luffy, though their circumstances differ greatly.
While the battle between Gaban and Imu unfolds, Oda quietly includes another important detail. Despite having a sword piercing his body and nearly losing consciousness, Luffy consciously commands his body to heal: “Heal!! Get better!! Just a little more!!”
This brief panel might be easy to miss on a first read. However, it connects to chapter 1111, where Luffy’s scars were shown to possibly disappear.
Putting these details together, Gear 5’s “imagination” power seems to allow Luffy not only to affect his surroundings but also to alter his own body.
This is not an immortality like Imu’s. Luffy cannot simply stand up after fatal wounds as if nothing happened. The scenes suggest this is a form of intentional healing that requires Luffy’s active effort to drive his body’s recovery.
Nearly four years since Gear 5 debuted, mainly shown as an offensive, freedom-driven, reality-bending power, this new healing ability could open a completely new path for Luffy.
Imu remains undefeated while Gaban has lost an arm. When Luffy returns to the fight, this self-healing power might be crucial for him to continue facing this formidable foe.
Although much about this new ability remains unexplained, it is certainly one of the most notable details One Piece has revealed about Gear 5 since its introduction.