The Dragon Ball franchise has embraced the recurring trope that many of its characters physically transform into even more powerful forms as they face increasingly formidable opponents. As one of the strongest fighters in the series, Gohan is certainly no exception. The eldest son of the franchise's main protagonist, Goku, Gohan has many of his father's Saiyan transformations, including the first two Super Saiyan forms; in fact, he was the very first to go Super Saiyan 2. However, by the end of Dragon Ball Z, Gohan gained the ability to power up to a different state entirely, unused by any other character in the Dragon Ball canon.
Dubbed by fans as Mystic Gohan or Ultimate Gohan, the transformation has the Saiyan warrior's facial features and hair transform slightly, similar to transformations as a Super Saiyan; however, unlike other forms, Gohan's hair retains its natural black color with the energy aura emanating from him a translucent white instead of the Super Saiyan's trademark golden hue. It is a form that surpasses previously established Super Saiyan forms, even allowing Gohan to go toe-to-toe with Goku at Super Saiyan Blue; and yet, it is perhaps the most undefined Saiyan transformation in the entire franchise.
Gohan gains access to the Ultimate form while training on the Supreme Kai's planet, accidentally freeing the imprisoned Elder Kai from the Z Sword. To thank him for freeing him, the Elder Kai spends over 20 hours undergoing a bizarre ritual to unlock Gohan's full potential, granting him the Ultimate transformation. Upon powering up, Gohan's energy signature changes entirely, initially making him unrecognizable from a distance to his longtime mentor Piccolo.
In this transformed state, Gohan easily overpowers Majin Buu in the creature's current form, forcing the monster to retreat. While later bested by Buu after the creature absorbs the powers and abilities of Piccolo and a Super Saiyan 3 Gotenks, Gohan retains his boosted power levels through the end of the Majin Buu saga.
By the start of Dragon Ball Super, Gohan hasn't trained in years, leading to a dramatic decrease in his power levels. As such, Gohan has trouble even transforming into a Super Saiyan when a resurrected Frieza returns to Earth, and is unable to undergo his Ultimate transformation. As the series progresses, Gohan regains the ability to transform to Super Saiyan 2 before beginning to train for the series' final story arc, the Tournament of Power.
Shortly before the Tournament begins, Gohan's strength has significantly increased, allowing him to transform into his Ultimate state once again and become even stronger than ever before, fighting Goku to a standstill, forcing his father to use the Kaio Ken technique while in his Super Saiyan Blue form to give him the advantage over his son.
Simply put, Ultimate Gohan is the character's most powerful form, dramatically stronger than other established Saiyan transformations including Super Saiyan 3 and Super Saiyan God. The Elder Kai's mystical ritual boosted Gohan's latent abilities to unseen levels, augmented by additional training, effectively making Gohan's previous transformations largely obsolete.
Depicted as being equal in power to Super Saiyan Blue in the anime, the manga makes the form even stronger, with Gohan in his Ultimate form able to defeat the powerful Kefla in her Legendary Super Saiyan form, a feat narrowly accomplished in the anime by Goku, who was barely able to knock the fused warrior out of the ring in his Ultra Instinct state. Signalling the full potential of Gohan's amazing abilities on display, the Ultimate transformation is a subtle way to differentiate Gohan from his father and Vegeta with his own incredible final form.
Dragon Ball Super Volume 7 is out on Blu-ray on April 2.