Dragonball Golden Age - U7s Most Powerful [SPOILER WARNING]

SPOILER WARNING:

Now this will only occur at the very end of the Golden Age story, but the entire plot of my story essentially follows the journeys of these five, while also developing the other heroes. However, at the end of the journey when the Tournament of Power is over and all the main villains have been defeated, these five stand out as the strongest in the Golden Age story (in Universe 7 at least).

And these are the forms that would be considered the most powerful for each of them at their peaks:

Gohan - Alpha Nova form - I've already coloured this form in the past and stated its origins; it being a combination of his Alpha Form and his Nova Saiyan form stacked on top of each other, both of which put his Beast Form to shame on their own. Granted he can reach higher levels of this state by tapping into both Super Nova and then Hyper Nova, the simple fact that only two individuals have ever pushed him this far in battle- Kiyo and the King of the Wild Hunt- speaks volumes as to how powerful he can get. Simply being in this form on solid ground causes matter to melt and disintegrate around him just by being near him, and he can produce so much power that it can cause the black void between universes itself to start fracturing. A simple punch colliding between him and Kiyo while in this form erases the known multiverse and propels them into the space between everything, and also resets everything by causing another Big Bang.

This is a last resort form. However, even when in this state, Gohan isn't the strongest (Kiyo still surpasses him, but she's not the only one)

Videl - Ultra Sense - a form Videl develops on her own. A unique variation of the Ultra Instinct state, this combines both Reina's Internal Martial Arts and her own state of awareness, giving her combat potential rivalling the Gods of Destruction and the Angels. Instead of relying on instinct, it relies on her own senses heightened to their absolute peak, allowing her to take opponents apart with only a handful of moves and takedowns.

She is by far and away the best martial artist out of the Z-fighters, even far surpassing Gohan in combat skill (though not power).

Celipa/Fasha - Omega Saiyan Form - another combination form, Fasha combines both her Alpha Form and her Space-Time Saiyan Form to create the Omega Form. Also a last resort transformation, Fasha achieves multi-reality levels of strength and ability. Think Ciri from the Witcher 3 and Cosmic Garou, but with Superman strength.

Zangya - Mystic Hera Form - yet another form I already covered, this form combines Zangya's unique Hera Magic and Ki control, pushing them beyond the limits of any in the multiverse. She surpasses Gohan in ki manipulation, making her the only on that can turn off Gohan's Nova form if it ever gets out of control. She is also the first one to push Kiyo in battle in the ToP and cause the dragon girl to experience joy in combat for the very first time.

Erasa - Cosmic Sorceress State- if we're talking about broken characters, Erasa is the equivalent of the One Above All. While this isn't her final form, it comes close to it. When tapping into her full potential as an Astral Witch, she can rewrite the laws of reality and causality. Considering she is their people's version of a Chosen One, destined to defeat Azathoth- a being said to have created all known realities across every conceivable timeline, including ours- she can destroy realities at will and recreate them if she so wishes.

She is, far and away, the most powerful in U7 and in Golden Age.