Warriors Unite! Birth of the Ultimate Super Saiyan 4!

Summary
Gohan in his True Super Saiyan 4 form, Goku in his Full-Powered Super Saiyan 4 form, and Vegeta in his standard Super Saiyan 4 form stand together as they perform the Warrior Fusion and fail the second step, but simply do it again and manage to fuse into Vekan. Vekan immediately proceeds to attack Alpha Shenron is able to overpower him instantly.

He fires his Galick Kamehamesenko at the Shadow Dragon sending him crashing into the ground before using Stardust Fall. He proceeds to dash at Alpha and kicks him in the gut before grabbing him by ankle and slamming him into the ground multiple times before throwing him at a mountain.

The battle continues as Alpha is knocked around like a ragdoll before realising that Vekan is fighting to kill him and decides to take the fight seriously. Vekan blocks a kick from the Shadow Dragon and hurls him directly at the ground before kneeing him the back as Alpha manages to get up and fly up to stratosphere as he launches his Ultra-Karma Ball at the fused warrior, but Vekan simply uses Super Breath to deflect it into space.

Vekan uses Soaring Fist against Alpha Shenron and sends him crashing against a mountain before stopping himself in mid-air. Vekan follows up with Shockwave Flurry and manages to destroy several mountains and debris created during the fight before hitting the Shadow Dragon numerous times before eventually, the Shadow Dragon falls to the ground due to his injuries. Vekan proceeds to prepare his Galick Kamehamesenko as Alpha Shenron stands up. Vekan fires his attack at the Shadow Dragon as the energy wave is about to hit him Alpha dodges it as Vekan teleports behind him and uses Big Bang Kamehameha before using 100x Big Bang Kamehameha against.

Alpha Shenron is critically injured by the attack allowing Vekan to follow up with Big Bang Kamehamesenko combining 100x Big Bang Kamehameha with Super Masenko instead of the regular Big Bang Kamehameha and Masenko resulting in a massive energy wave hit the Shadow Dragon and decimates most the area as Alpha Shenron is swallowed by the energy wave. The former lakeside town and lake disappear in the energy wave - most of the Southern Continent inhabitants are able to see the explosion while one of the inhabitants complains that the lake was a national park.

Animals at Yajirobe's Prairie as a massive shockwave knocks down the trees and small fissures ravage the area. The energy "dome" settles as it reveals that one of the replicas of the Black-Star Dragon Balls have been destroys as Omega Shenron emerge from the smoke and compliments on reverting him to his previous form as Vekan compliments him on surviving the attack as he proceeds to tell him that one more will surely end him.

Omega uses his water manipulation to create large pillars of water from the moisture in the ground and uses it to defend himself, but Vekan simply uses an energy sphere to force the Shadow Dragon to move. Omega Shenron notices something off about Vekan and slowly realises that his energy has decreased due using his last energy wave, but also decreased over the course of his fusion.

King Kai explains to Gregory that fused warrior's power will gradually decrease over time if the fusees were in their base form, but since Vekan's fusee weren't his power is decreasing rapidly and his previous attack has cut his power down immensely.

Vekan realises his own weakness and attempt to go for the killing blow by using Super Galick Kamehamesenko and unleashes it on Omega Shenron, but he uses Orb of Water before the attack hits him. The energy wave manages to destroy the top of Mount Kiwi as it is redirected into space.

However, as the smoke clears Omega Shenron emerges from some rubble revealing that it left battered and bruised before swallowing the six remaining replicas and transforming him into Near-Alpha Shenron. Both of them a severely weakened and Alpha even admits that True Super Saiyan 4 Gohan would be enough to kill at the moment.

Syn attempts to make a near replica to replace the one that was destroyed, but Vekan manages to stop before becoming severely weakened. King Kai urges him to separate or he'll die - causing Vekan to force his fusion to end prematurely. Goku and Vegeta appear to be almost drained and makes a remark about being the Ultimate Super Saiyan 4 is worth it, but takes its toll.

Gohan reverts to a regular Super Saiyan 4 as he prepares to take on Syn once again.

Battle

 * Vekan (Super Saiyan 4-Full-Powered Super Saiyan 4-True Super Saiyan 4) vs. Syn Shenron (Alpha/Omega/Near-Alpha)