When Trunks and Vegeta entered the Hyperbolic Time Chamber for the first time, they were really in for a shock.
"Whoa, this is unreal!" Trunks exclaimed as he walked on to the white plain. "It's like it never ends! I...I need time to adjust...to get ready to-
"TRAINING STARTS NOW!" Vegeta kicked the side of Trunks's head, sending the half-Saiyan flying across the ground.
The young Saiyan got up and rubbed his head, hoping he didn't have a concussion. "Was the kick really necessary?"
"I FEEL EMPOWERED!" The prince transformed into a Super Saiyan, the wind knocking his son down again. Then, Vegeta flew away and started training by himself.
"He's quite the enthusiast." Trunks then got up a second time and went into the building to give himself a mini-tour.
"GALICK...GUN...FIRE!"
Once he was a good distance away, Super Saiyan Vegeta shot his signature move away from the entrance to the white emptiness, testing himself to see how far he could take it.
'I must be weak,' he observed silently. 'The ground didn't even shake. I must become stronger!'
'You're not weak, Vegeta!' said the voice in his head. 'Even back before you fought Kakarrot on Earth – wow, that was a while ago now – you blew up a planet! Now, you're a Super Saiyan!'
'God damn it, Nappa. You couldn't have just stayed away from me for a year, could you?'
'Well, you'd be in here for only a day outside of here,' replied the bald ghost. 'Also, I didn't want to miss your son's progression through life.'
'You're starting to sound like that nerdy half-Saiyan son of Kakarrot,' the prince sighed.
'It's not my fault that I learned a lot at Saiyan University!' Nappa objected.
'Whatever.' Vegeta suddenly started concentrating energy into his hands. 'I need to train to be stronger than Cell, not get an aneurism from talking to you.' After a minute of charging, Vegeta decided to put a twist on his attack: instead if slowly forcing his Ki out in the way he usually did, he let all of it just flow out at whatever speed it desired.
The resulting energy beam was much less controllable and released much more heat than a normal Ki blast, but weeks later, Vegeta figured out a way to use invisible walls of Ki to direct it in one given direction. Even then, though, it wasn't easy to control.
Vegeta and Trunks soon found the buff Ascended and Ultra Super Saiyan forms on their own, not even bothering to tell each other. Heck, they only ever saw each other the few times they sparred and when they were resting simultaneously in the small building.
"So...how's your training going?" Trunks asked on Day 153 while they each ate a large sub for lunch, the first meal they'd eaten together since...well...never.
Feeling a bit generous, Vegeta said, "Got stronger. Figured out a new technique. Discovered a new transformation. The works."
"Wait, you found a way to surpass a Super Saiyan?!" The blue-haired Saiyan's jaw dropped. He was wondering if Vegeta had found the same buff form as what he was using, too.
"Yeah, it's where my muscles expand to be almost as big as m'dick. Actually, m'dick is WAY bigger. Why?"
"I discovered the same thing!" exclaimed the now-excited S.O.B. (son of a Bulma). "It's a bit slow, though."
"Kid, let me tell you something." Vegeta leaned forward. "Speed isn't always a deciding figure in a fight. If you can overpower your opponent by a large enough of an amount, speed doesn't even matter. Their attacks won't be able to do shit to you." Suddenly, Vegeta's plate was clear. "SPARRING TIME!" he shouted abruptly, grabbing Trunks by the neck and speedily taking them both outside.
Trunks transformed into a Super Saiyan and escaped the grip. "All right," he said. "Let's see how you do with the buff form." He started powering up to the Ascended form, followed immediately by Vegeta.
"Ready?" the man from the future asked once they were both done.
"Do you really think the Prince of all Saiyans would not be ready?! HAAAAA!" Vegeta burst off of the ground, kicking up some dust in the process.
"You know, technically I'm a p-" Trunks's sentence was cut off by Vegeta's right leg hitting him directly in the left cheek with the force of an entire army, throwing the half-Saiyan a good 30 yards (27.69 meters (hah, 69)). Despite this, Trunks took minimal damage.
"You talk too much." Vegeta then charged at his fallen son, reaching him within half a second. Immediately following this, the Prince sent his fist flying through the air faster than sound, stopping only when the younger Saiyan caught the punch.
"Don't be so surprised," Trunks said, smirking. "It's not like you're the only one who trained." He got up and used his momentum combined with Vegeta's to throw his father.
"Insolent fool!" Vegeta wiped some dust off of himself. "You think you're a match for the great Vegeta?!"
"If I'm a fool, I think I know where I get it from!"
"Oh, I see where you're going with this, and I will not tolerate this from my own flesh and blood!"
"Well, then maybe you shouldn't have boned Mom!"
"She was the only creature on this pathetic world who could handle my dick! Not even one of those blue whales could do it...not that I tried or anything."
Both of them paused, Trunks imagining a Saiyan-whale hybrid before vomiting from the idea and Vegeta realizing that he'd just embarrassed the shit out of himself. Not literally. Why do you think a Super Saiyan would make a dukey in his pants?!
Trunks powered down to a mere Super Saiyan. "This is awkward..." he said slowly.
"You're telling me." Vegeta followed his son's example. "Now...impress me with something."
Trunks nodded. "I made a technique that you might like."
"Oh, do go on."
Trunks flew away from his father and then activated a circular aura around himself. "HAAAAAAA!" The aura quickly grew around him, coming only a stone's throw away from the Prince of all Saiyans. Then, the controller of this special technique let the ball of energy surrounding his body dissipate into nothing.
"What do you think?" he asked his father.
"That technique...what do you call it?" asked Vegeta, ignoring the question arrogantly.
"I actually haven't named it," Trunks replied, scratching the back of his head.
"Too bad, now its name is Galick Storm."
"But...why?" The man from the future was confused.
"Because I say so, that's why. Besides, it's not as cool as what I'm about to show you." Vegeta suddenly activated his Super Saiyan aura and cupped his hands by his side as if he was preparing a Galick Gun.
"But isn't that a technique already?" asked Trunks.
The Prince responded simply, "Watch closely."
Trunks could sense the energy gathering in Vegeta's hands, but it felt...different...in comparison to a Galick Gun. It felt warmer, almost like if a star had a Ki signature.
Finally, Vegeta flung his hands forward and screamed: "GALICK SUPERNOVA!" Glad he wasn't in the way of the blast, the half-Saiyan marveled at the beautiful yet deadly mix of orange, yellow, and red energy. It even radiated heat, which surprised him.
When the energy died (take that, Black-Eyed Peas!), Vegeta powered down to his Base form, panting from exhaustion.
Trunks powered down and approached his father. "That was incredible!"
"Of course it was, you nimrod," the Prince of all Saiyans said.
After that, they decided to train together and teach each other the new techniques. During this time frame, Vegeta also revealed the Final Flash technique. You can guess the rest from there because this chapter is already pretty long and I don't want to make a Part 2 for the special.
Hey, guys! I hope you enjoyed the first special in Rise, Shenron. It took a while for me to come around to writing this; I spent a lot of time making it and elaborating on the story and character development. After all, this is Trunks and Vegeta's time to shine.
So that's where Trunks and Vegeta got those two original, new techniques that you've never hear of. Trunks isn't the same Future Trunks as in canon, so that's why he developed Galick Storm. Vegeta just wanted to find something that could help him beat both Goku and Frui (he's got a grudge on Frui after what happened on Namek), so he developed an extra technique.
I don't feel like coming up with Power Levels for this chapter. #2Lazy5That