- For this hypothetical scenario, we rewind back to the Trunks Saga after Future Trunks has just slain most of the Frieza Soldiers present and then turned into a Super Saiyan.
This time, however, Goku - rather than waiting to see what would happen while traveling back home - uses Instant Transmission to reach Earth quickly after locking onto Frieza's energy; surprised to see another Super Saiyan and with both now dealing with Mecha Frieza, which ends with Future Trunks still cutting him down to size before turning him to ash.
- Angered at his son's death but seeing an opportunity, Cold asks if the Saiyans wish to join his side as the rulers of the galaxy - an offer both Goku and Trunks refuse.
Instead, Goku wants to fight King Cold and tells the gargantuan monarch to go full power like Frieza did; something Cold initially refuses to do as he thinks Trunk's sword is the only reason they beat his son - with Trunks (at Goku's request) putting his sword to one side as they battle Cold.
- Quickly realizing that they weren't reliant on just the sword, Cold indeed goes to his Final Form and eventually powers up to 100%; angered that his superiority is been challenged.
For Goku, this was part of the plan - reasoning that Frieza never trained to use his 100% form and burned through his energy quickly due to his own hubris and lack of training, with Cold soon in the same situation but worse off as he's against two Super Saiyans at full power rather than one.
- Eventually, Cold is left battered, bloodied and beaten on the ground as he reverts back to his Second Form; horrified that his strongest form wasn't enough as he begs for mercy while offering the two Saiyans dominance over multiple planets and promising to change his ways.
Trunks is more than happy to kill the old Emperor as he doesn't buy his pleas, but Goku tells him not to - remarking that he has turned enemies into allies before and he wants to see if Cold could be swayed to change now that he's been humbled in combat; informing a reluctant Trunks that if Cold doesn't change, then Goku will seek him out and finish him off.
- Choosing to trust Goku despite his own judgement, Trunks relents; Goku telling Cold to leave and make good on "turning over a new leaf", or Goku will seek him out and destroy him.
Agreeing to this, Cold crawls onto his ship - not even having the energy to blow up the planet - and weakly sets the controls to return home; his Mothership flying away from Earth while Goku receives an earful of complaints from his allies about letting King Cold leave alive, with Trunks eventually informing them as to why he's there and giving Goku the Heart Medicine before recovering his sword and traveling back to his timeline.
So, do you think Goku's decision to offer King Cold an olive branch would have a positive effect on the story going forward, or would this be a case of Goku's mercy to an enemy coming back to bite him in the rear?
Curious to see what you guys think.