Goku Jr achieved this level when sparring with Ryun and accidentally looked at the full moon. uncontrollable, he started to set out on rampage when he was cooled down by Vegeta Jr and Ryun he transformed into this form. There is another version of the Super Saiyan 4 form. Evil Super Saiyan 4 is a form that was achieved by SVX through the influence of an evil spirit. It is significantly stronger than a regular Super Saiyan 4 and is different than it in appearances.
Appearance and Power
In this form, the Saiyan's hair returns to its original color, the tail regrows and the body is covered in a shade of red fur. A Saiyan in this form also possesses a shadow trim around the eyes and over the eyelids that varies in color. The hair is lengthened, but not nearly as long as Super Saiyan 3. The aura in this form loses the arcs of electricity, instead becoming pure fire with gleaming sparkles.The great power and speed enhancements brought on by this form easily make it the very most powerful Super Saiyan form in the series, capable of destroying multiple Solar Systems. For example, while Super Saiyan 3 Goku was almost unable to even phase Baby Vegeta, as soon as Goku transformed into a Super Saiyan 4, it became almost the opposite, with Baby Vegeta being almost unable to hurt Goku at all. Goku also develops an attack he calls, "10x Kamehameha", as it is ten times (10x) stronger than a normal Kamehameha Wave. The users of Super Saiyan 4 can develop attacks that only this transformation can use. Super Saiyan 4 multiplies the power of a Super Saiyan 3 by five to ten, depending on the amount of training that the user does.
Throughout mid Dragon Ball GT, Super Saiyan 4 become Goku's weapon of choice as the villains became even stronger. After being pushed to the limit by Baby, Golden Great Ape Goku transformed into a Super Saiyan 4 after Pan calmed him down. In this form, Goku completely dominated over Baby (none of the villain's attacks could even hurt him) and eventually killed him with a Kamehameha wave.Goku's next opponent would be Super Android 17, who proved to be Super Saiyan 4's first real challenge. Because of his energy absorbing abilities, Super 17 was able to turn all of Goku's energy attacks into his own power, making him stronger by the minute. Eventually Goku reverted to his original state and killed the android using his Dragon Fist attack followed by a Kamehameha. Super Saiyan 4 proved to be incredibly helpful when Goku used it to take down most of the evil shadow dragons. Eventually however, he met his match in Syn Shenron who absorbed all of the Dragon Balls becoming Omega Shenron. Omega's power proved to be greater than that of a Super Saiyan 4's, and Goku was thrashed around for most of the fight. Using Bulma's Blutz Wave generator, Vegeta was also successful in attaining Super Saiyan 4.( Which was because it takes 3 days for full moon day to appear and they did not have time for that). However, even as a team, Goku and Vegeta still stood no chance against the dragon. It wasn't until they fused into Super Saiyan 4 Gogeta that their power surpassed Omega Shenron's on a massive scale. However, Gogeta spent too much time playing around with Omega Shenron and the fusion wore off in minutes due to his own tremendous power, and he ultimately failed to finish him off in time. Goku eventually killed Omega Shenron with the Universal Spirit Bomb. It is unknown if, with proper training, Goku and Vegeta could have become powerful enough to match Omega Shenron without needing to fuse, as the saga ends with Omega's defeat and Goku leaving with Shenron.