During Vegeta's battle against Buu...
The Supreme Kai and Gohan stood in a lush field beneath a beautiful violet sky. Having been teleported against his will, Gohan grabbed the Supreme Kai by the collar of his shirt and lifted the tiny man to his eye level.
"What's your problem we can't just leave Vegeta to fight Buu on his own! We have to go back!" the Saiyan roared.
"Unhand the Supreme Kai this instant!" Gohan heard a familiar voice say. He glanced over the Supreme Kai's shoulder to see Kibito standing with his arms behind his back, scowling at the Saiyan.
"Kibito? I thought you were dead." Both the Supreme Kai and Gohan spoke simultaneously.
"I am unsure of it myself... One moment, I was killed by Dabura, and the next, I was alive. Strange."
"It must be the work of the Dragon Balls. I'm guessing Bulma and the gang must have used them to revive everyone who's been killed since this entire ordeal started. All the good ones at least."
"Please, unhand the Supreme Kai. He will explain why you have been brought here. I would like to hear why a moral is here as well."
Gohan groaned as he released Shin; the Supreme Kai landed with a resounding thud on his behind.
"Thank you, Kibito. It's great to see you again," Shin said before looking at the Saiyan. "Right now, we are in the World of the Kais. As for why you have been brought here, it is because we have a way for you to defeat Buu. You must use the Z-Sword."
"The Z-Sword?" Gohan repeated.
"Yes. It is an all-powerful weapon capable of killing even Majin Buu. However, it is sheathed in stone and hasn't been used in millennia. It is said that only a warrior powerful enough to remove it from where it lay is strong enough to wield its power. Come, let's see if you are the warrior of legend."
Shin led the way, flying through the World of the Kais with the others following him. Gohan looked around, finding many similarities between this grassy planet and Earth. However, unlike Earth, this world had multiple moons orbiting it, each visible during the day.
The three of them eventually found themselves standing before a stone pillar; at its center was the Z-Sword, lodged inside.
"So, all I have to do is remove this sword from this rock?"
"Correct."
Gohan knelt and wrapped his fingers around the blade's handle. "So, this sword is super sharp or something?"
"Not necessarily," said Kibito. "It combines its strength with the deepest, hidden strength of its wielder. However, I highly doubt you'll be able to pull it out."
Kibito had this smug look on his face. Gohan looked at him with the sides of his eyes and entered his Super Saiyan 2 form. "We'll see about that!"
Gohan started to pull the blade with everything he had, yet the blade would not budge. Kibito continued to act arrogantly, watching Gohan struggle to remove the blade as he once did when he was a young warrior.
"Think about all of the people that Buu has hurt, Gohan. Think of the people he will harm if you aren't strong enough! Your friends, your family, your lover... All of them will be killed if you don't act now!" Shin told him, stirring the rageful pot within Gohan.
Gohan's eyes widened and his body started to emit purple lightning, which immediately compelled Kibito to wipe that complacent smirk off his face.
Now in his Tempered Super Saiyan state, Gohan began to crack the floor beneath him before the blade was removed from the rock tower, reducing it to rubble. As he held the blade tightly, Gohan looked at Kibito with a cocky grin as he returned to his normal state. "Looks like it's mine now, Kibito."
The three of them landed in the grass below, but Kibito noticed something peculiar about the way Gohan was holding the blade. "It looks like the boy is struggling to hold it," he said.
"Well," Gohan mumbled, struggling to lift the blade past his waist. "It's pretty heavy. You can try it."
Gohan handed the blade to Kibito. The moment it changed hands, the sword and Kibito fell to the ground.
"Looks like he's struggling to hold it," Gohan mocked.
"That's enough you two," the Supreme Kai interrupted. "Gohan, if you want to beat Buu, you're going to need to become one with this blade. Your training starts now."
Just as those words left Shin's lips, a sudden and powerful presence appeared behind the trio. When they turned to face this presence, Gohan's eyes watered and widened.
"Dad!" he called out, seeing none other than Son Goku himself standing before him with a halo over his head. Gohan ran over and embraced his father. Goku smiled softly and wrapped an arm around his son.
"Hey, Gohan. So that incredible presence was you!" Goku couldn't hide how proud he was, smiling with shut eyes.
"How are you here? Aren't you supposed to be dead?" Gohan asked.
"Well, I'm still dead, as you can see by this halo over my head. But I guess this place is connected to Other World. Say, what is this place anyway?"
"It's the World of the Kais," Shin answered.
"Hmm..." Goku looked around for a moment before looking back at Shin. "Isn't this place a little big? And where's King Kai?"
Shin and Kibito both stared blankly at Goku before the Supreme Kai answered. "The World of the Kais and King Kai's planet are two different things..."
"Oh... I see." Goku continued looking around. "I think I get it. You guys are King Kai's minions or something."
"How dare you refer to the Supreme Kai as a minion!" Kibito yelled.
"Supreme Kai? Is a Supreme higher than a King? Is there a Prince Kai?" Goku mumbled.
"Why is this man even here!?" Kibito shouted.
"No, this is good," Shin told him. "I imagine Gohan would be more motivated if he could train with his father, correct?"
"Yeah!" Gohan nodded. "Just like old times! I swear, I won't let you down this time, Dad!"
Goku tilted his head. "This time? When have you ever let me down?"
"When I let you die to Cell... I could have saved you. It's all my fault, I'm sorry."
"I'm confused. I only died because I wasn't strong enough to beat Cell on my own." Goku told him. "If it wasn't for you, Chi-Chi and everyone would be dead too. You saved everyone. How could I be let down knowing that my son is the strongest guy in the world?"
Gohan smiled solemnly, looking down at the sword in his hands. "Well, I was the strongest. Not anymore. I haven't been keeping up with my training."
"That's not true based on the energy I felt just a second ago. It was way stronger than what I felt when you fought Cell."
"But that's impossible," Gohan told him. "I haven't done anything to get stronger."
Goku placed his hand on his chin, looking his son up and down. "Well, right now you aren't that impressive, but whatever you did before I got here was incredible. I want you to show me. Whatever you just did, do it again."
Gohan nodded before instantly entering the second stage of a Super Saiyan. He smiled at his father, "How's this?"
Goku wasn't amused. "That's it?" he asked. "That's not the same thing I felt from across Other World. Are you sure?"
"All I did was go Super Saiyan 2," Gohan admitted.
"I wouldn't be so sure. You look different than you were when you removed the Z-Sword. Back then, it was like you became a whole different beast for a moment." Shin rubbed his chin and relived that moment in his mind. "Yes... It was after I mentioned that Majin Buu would kill everyone you loved. Your body changed after that."
"Majin Buu?" Goku asked.
"He's the new bad guy attacking Earth. That's why I'm training. So I can beat him."
"So he's strong!?" Goku asked.
"Very. Even stronger than Cell."
"Wow! Man, I wish I wasn't dead..." Goku sighed and pictured what Buu must've looked like in his head. He pictured someone tall and muscular, just one look at the thing was enough to kill someone with fear. However, this depiction of Buu was far from accurate.
"Gohan. You should try to enter that state you were in when you removed the Z-Sword from the stone. Whatever it was that you thought about, do it again."
"Alright," Gohan said as he closed his eyes. He started imagining Majin Buu destroying the Earth, killing animals, killing the innocent, and then killing those he cared about. He witnessed the death of Piccolo first, and then Trunks and Goten were murdered alongside him. Krillin and the other Z-Fighters were killed in quick succession and all that was left were their families. Bulma, Chi-Chi, and Videl were helpless, hiding from Buu until they were inevitably found and killed.
The electricity around Gohan's body started to change color once more. He aimed his face toward the sky and released a resounding bellow that was heard throughout the entire planet. Once he settled into his new form, Gohan stood with the Z-Sword resting over his shoulder as if it were weightless.
"How's this," he asked his father. His voice was deeper than usual; it was as if he were possessed.
"Amazing!" Goku started circling his son like a madman, getting a good look at his new form up close. "Wow! What is this Ki? It's just as the Supreme Kai said, it's like you're a whole different beast, now! Hey, that's a good name for stuff. Beast Ki."
"Beast Ki? That's a little embarrassing..." Gohan mumbled.
"If I didn't know any better, I would think this is a Super Saiyan 3, but it's not. You still look like a simple ascended Super Saiyan but much stronger!"
"Super... Saiyan... 3?" Gohan asked. "Is that a real thing or did you just make that up?"
"Oh, so you guys back on Earth still haven't figured it out yet, huh?" Goku laughed mischievously before taking a large step backward. "Well, it'll be easier if I just show you."
"He can't be serious..." Shin said to his assistant.
Goku immediately transformed into a Super Saiyan, the smile fading once his hair turned golden. "As you know, this is a Super Saiyan."
Goku's body erupted, his hair grew slightly, and he entered the state just above a Super Saiyan. "And this is the ascended version of a Super Saiyan. A Super Saiyan 2."
Goku looked downward, clenching his fists and grimacing as he began releasing an incredible amount of energy. "And this!" he roared, his voice causing the trees around them to flutter their branches as if they were caught in a typhoon.
"This is even further beyond!" Goku released so much pressure from his body, that Gohan and the others could hardly keep their footing. He started to scream; his yell was even louder than Gohan's and it too was heard echoing throughout the entire planet.
Gohan could feel the hairs on his arms and legs stand as his father's hair grew past his shoulders and down his back. Eventually, Goku's brow extended forward, growing over his eyebrows and one final explosion signified the ending of his transformation.
Witnessing the incredible change in power, Gohan, Shin, and Kibito watched with their mouths gaping. "This is insane..." Gohan whispered. "Dad... you're incredible."
"Thanks, Son," said Goku. "As you may have guessed, this is a Super Saiyan 3."
Gohan looked at his father's smile and immediately knew what was going to happen next. Without a word, Gohan gripped the Z-Sword tightly and held it in a ready stance. In his new form, the sword felt weightless.
His father exhaled through his nostrils humorously and struck his iconic battle pose, bending his knees and placing two curled fingers in front of his body.
"So, Son. What's your new form called, I'm dying to know."
"Well, considering I have to focus my rage more than usual, how about we call it a Tempered Super Saiyan?" Gohan's voice roared through the echoing crackling of his violet electricity, compelling his father's grin to double in size.
"I like the sound of that," Goku said. How about we see what's stronger, a Super Saiyan 3 or a Tempered Super Saiyan."