( If you are confuse why Ryuu only has around 1k of power level or 2k is because he did not come from planet vegeta which has 10x the gravity of earth, and the reason he can't yet defeat goku is because that's there first time sparring.
They only practice a set of martial arts, and he is a 2 year old kid when he spar, and he is 3 years old now meaning he can defeat goku because of constant sparring and he also practice ki from 3rd year of the timeskip, hope that helps)
As Ryuu and Raditz get into their fighting position, Ryuu dash first with a punch, which Raditz block and followed up with a kick towards Ryuu's body.
Ryuu dodge the kick by leaning backward. Followed up by backflip and run in circle as Raditz being the center. As he was running, he trip, making him roll.
"Hahahah, watch your step kid, this is a fight so if you make a single mistake will result you in death, now get up" Raditz laugh while explaining.
"I know, I was just distracted by the tail your swaying" Ryuu with a blush come up with an excuse. As he get up, he dash again but this time watching his step.
Ryuu then kick towards Raditz face which he dodge by leaning sideways as he grab the leg, and try to hulk slam him. Which Raditz fail as Ryuu instead ki blast the abdomen and got out.
"Ugh, that hurt a little than the green pest I met" As he said that, he dash towards mc with a straight punch while flying, while mc dodge it with a duck and grab the tail, making Raditz go weak.
"Hehe, I win so called uncle" Ryuu said while holding the tail, even if you call mc shameless, in war all dirty tactics is all fair.
"Ugh, yo..you shameless brat!, Let go of me!" Raditz said while he's getting weak by the tail.
"Nope, I will let you go if you admit defeat" Ryuu said with an evil smirk on his face, while swaying his tail towards the face of raditz and smacking him softly, mocking him.
"Grr, you.. you win!, now let go of me before I past out!" Raditz said while Ryuu let go of the tail.
"Fufufu, you promise that if you lose..." Ryuu said pausing in the end to let Raditz finish it.
"You!!, Fuuh, That I will stay on earth and join you guys and to be a good uncle, you happy now you cheeky brat" Raditz angrily said and sat down to regain his stamina from when his tail is caught by Ryuu.
"Yes!, haahah I win, Dad look I win and he promise the bet" Ryuu said as he goes to Goku and Co., while jumping around like he got a new toy(sparring partner) for him.
"Yes yes, you win but don't be like that in the future, it's a dirty fight" Goku said while patting the head of mc.
"Ahhh, stop patting my hair, huh, who's that green guy dad" Ryuu pointed towards the guy who's at the top of bulma's flying vehicle.
"Huh where?, Ahh!, it's pipolo!" Goku exclaim as he point at the top.
"It's Piccolo you idiot, don't make a mistake on my majestic name or I will kill you" Piccolo angrily said and hop off the vehicle.
"So you are Goku's sons huh" Piccolo said as he look at Gohan and Ryuu together with Goku.
"Ahh it's Piccolo, look master Roshi it's Piccolo." Krillin who is watching from the vehicle said to Master Roshi.
"Yeah yeah, we see that Krillin, but is he here?" Master Roshi said.
While bulma is left out from the conversation and just look over the four.
"Ahh!, it's the green pest who block me from my path" Raditz who's getting up from sitting look at Piccolo who hatefully glared at him.
"Grr, atleast I was not defeated by a kid who's looks no older than 4" Piccolo said.
"You!, Atleast he is stronger than you by a miles than you could ever be" Raditz fight back with words.
"Heh, atleast I didn't fight him like you are who just lost" Piccolo exchange with words.
"Atleast, I'm not a coward like you. As we saiyan are a warrior race than you green pest" Raditz haughtily said with his arms lock up looking smug.
"Wh.. why you!" Piccolo said as he attack raditz with a barrage of ki blast.
"Hahaha, you coward, that's only you can do, attacking first to a guy like me who fight recently" Raditz said as he dodges the attacks and deflecting some.
As Piccolo and Raditz continue to fight, Goku, Ryuu, Gohan, Krillin, Master Roshi, and Bulma watch the two dumbfounded by what happen to the two.
"What just happen, anyway, you kids better get ready for tomorrow's study or chichi will get mad at me" Goku said as he pick his sons to his shoulders, Ryuu on the left and Gohan on the right.
"You're so cool Ryuu, you defeat that man with a cool dodge and grab" Gohan said with a sparkling eyes.
"Hehe, you should learn from the great me, of the art of shameless" Ryuu said while looking like he was the hero while his arms on his hips, but become embarrassed by his pose
'Ugh, that was embarrassing' Ryuu thought and sat down again.
'Anyway, is my wish of using magic is true, let's try materialization' Ryuu thought and try to do the materialization. He stretch his arms out and try to bring out magic by using the same he did for ki blast and a puff sounded and a perfect size black goku suit appear out of thin air.
"Wah, how did you do that" Gohan who's to the right shoulder of goku and watching Ryuu from the start said.
"Woow, what is that Ryuu" Goku also ask, and look at his son.
"Hehe, I'm a magician, magician don't expose there secret" Ryuu said and go to the flying vehicle of bulma to try the suit of goku black.
While they kept talking the fight of the two is still ongoing, but they did not bleed one bit from the fight, as they did not use there full power.
Walking to the vehicle, he knock on the door, and krillin open the door for Ryuu.
"Hello there Ryuu, you are quite strong than you're father" Krillin said as he let Ryuu in.
"Thanks, anyway where is can I change my clothes, uncle bald" Ryuu said as he look at the vehicle.
"I don't know, let's ask bulma where it is" Krillin said as he walk towards bulma who is watching the fight.
"Bulma, Ryuu wants to know where the he can exchange his clothes" Krillin said.
"Just go to the second room, it should be where you can change your clothes" Bulma said to Ryuu who is following krillin.
"Thanks, I gotta go now" Ryuu said as he walk towards the second room, the flying vehicle has three room, the controller room where Bulma, Krillin, and Master Roshi is. The second room is the change room for clothes, while the third would be a place to sleep.
Walking to the 2nd room, he open it and get inside and close it. He change his original clothes the same gohan has and change his clothes.
Finish changing, he walk out of the room and shouted to the three that he will go back to his father and brother, getting him an okay.
He flew towards Goku and Gohan who is currently flying with nimbus and hop on.
The fight of the two has finally ended by Raditz winning.
"I win, green guy" Raditz said with his arms cross.
"Tch, I'm not green guy or green pest, I'm Piccolo" Piccolo said and walk towards Goku and Co., while Raditz also follow to him.
Arriving there Raditz said to Goku that there is another saiyan who will come and they are stronger than him by 10x.
"You all should train to get stronger, since the two saiyan will get here in 1 year if not 11 months" Raditz said while taking his scouter off from his face.
"So there will be another threats who will come and two at that, this is getting tricky" Goku said, as he look at his son.
"By the way do you have some scientist here, so that I can give this to them and mass produce it, it can do communication, reading battle power and many more function." Raditz explain as the scouter to them, as the three at the vehicle walk out to them.
"Bulma is a scientist, you can give it to her" Goku said and look at the incoming three.
"That blue haired girl is Bulma, you can give it to her" Goku pointed to Bulma.
"Okay, I'll go to her and give her this scouter and my space pod" Raditz said and walk to bulma who is startled but keep walking towards him, he hand out the scouter and tell her the functions of the scouter and mass producing it for money and also tell her the space pod that can travel planets to planets.
"This alien technology is good, you can even travel from planets to planets, I will try to mass produce it and if it's good then you can have a 50% share from the money if this thing can be a big hit" Bulma explain to Raditz who is please.
"Good, I hope you will do it if not I will destroy this earth" Raditz said while a ball of ki charge up.
"Hey uncle, no threatening of destroying earth remember" Ryuu said who is listening to the two talking.
"Tch you're lucky my nephew is here, you better do it" Raditz said and walk towards Ryuu.
"Hmm, I will don't worry about this thing, if you have more of alien technology give me so that I can study it" Bulma said a little scared by the threat.
And just like that this chapter ended.