Dragon Ball has brought Gogeta - Goku and Vegeta's Fusion Dance form - back and made him better than ever, in the latest episode of the Dragon Ball Heroes promotional anime. The current storyline of Dragon Ball Heroes has seen the mastermind villain Fu create his own mirror universe, populated by a fearsome lineup of classic Dragon Ball villains (like Freeza and Cooler), previous Dragon Ball Heroes villains (Cumber and Hearts), and a new alternate version of Goku Black, complete with his own Super Saiyan Rose 3 form. With that level of threat in front of them, it's no surprise that Goku and Vegeta would need to fuse, and take Gogeta's power to the next level!
In Dragon Ball Heroes Episode 38 Goku Black is still wreaking havoc on his fellow combatants in the mirror universe, showing himself able to withstand both Goku's Ultra Instinct and Vegeta's SSGSSE tag-team assault. When Black summons a demonic Destroyer to the battlefield, Goku and Vegeta realize the threat is too real - especially when Golden Freeza and Gold Cooler get taken out by the monster in a single strike. So, Goku and Vegeta use the Fusion technique to merge into Gogeta - the Super Saiyan Blue version of Gogeta we met in Dragon Ball Super: Broly!
In order to take down Goku Black, Gogeta must go beyond their previous limits; Gogeta realizes to his horror that the fused warrior is evolving before his eyes during battle. At the climax, Gogeta manifests a furious golden aura, with enough new power for Gogeta to pummel SSJ3 Goku Black to the point of disintegration.
This is everything that Dragon Ball Heroes is about. This new limit break and golden aura Gogeta power are in no way part of official Dragon Ball canon - but it is both a logical next step and fan-service payoff for where the canon has currently left Gogeta.
Ironically enough, in the actual Dragon Ball Super manga storyline currently running, Goku and Vegeta have never been further from achieving new Gogeta power. The two Saiyan warriors have embarked on diverging paths of developing their respective abilities: Goku is mastering the angels' zen-minded power of Ultra Instinct; Vegeta has unlocked that wild abandon power of a Destroyer God in Ultra Ego. It's been really interesting to see Goku and Vegeta (slowly but surely) start to grow into more interesting individual characters as a result of these new power transformations - could be even more interesting to see what happens if (when) their contrasting powers unite in a Fusion again.
Watch Dragon Ball Heroes new episode HERE.