Nappa complies but decides to take out Krillin and Gohan instead. Goku cannot catch up to Nappa and uses the Kaiō-ken technique to ram into Nappa, breaking his back and rendering him useless. Goku throws Nappa at Vegeta's feet.
'Kaio Ken, it seems I should learn this technique, it's amazing. Also, this technique has no limits.' Eero thought to himself while sitting on the edge of the cliff, watching the battle below while eating Peanuts.
When Krillin asks him what he did, Goku replies, 'Kaio-ken utilizes all the potential energy within him and multiplies his reflexes, speed, senses, and power.'
'It's an amazing technique.' Eero thought to himself, his eyes lit up.
However, Goku then comments that Kaio-ken's weakness is that it damages his body if multiplied to an extent he cannot handle, and this might even kill him by causing him to explode with the pressure.
Listening to the side effects, Eero realized something; his eyes lit up and his heart filled with excitement, 'This technique may be perfect for my body because more damage, more pain increase my body and soul attribute, universal body uses everything as fuel. Looking at the red aura flickering on Goku's body, let's see what is the effect of Kaio Ken.'
Nappa begs for mercy, but Vegeta throws him up into the air and destroys him with a single concentrated blast. Goku tells Gohan and Krillin to return to Kame House, and they say their farewells as Vegeta then sets his sights on Goku.
Goku tells Vegeta that he wants to fight elsewhere so as not to destroy the bodies of his friends.
They head off to a desert, while Gohan and Krillin fly back toward Kame House.
Vegeta implies that not many low-class warriors like Goku get to spar with the elite like Vegeta, but Goku replies that even a lower-class reject can surpass the elite if he tries hard enough.
Goku and Vegeta begin to fight and appear to be evenly matched. Vegeta tells Goku to release his hidden power, to which Goku complies. He engages the Kaio-ken; however, Vegeta manages to defend against it.
Vegeta powers up a great deal himself, and Goku uses the Kaio-ken x2; however, he still is not a match for Vegeta. Finally, Goku concentrates all of his energy into a Kaio-ken x3, raising his power level to over 24,000, which worries King Kai.
'It's interesting. It's more fun to watch battles than in the anime; you can feel the Qi clash. I am excited to see the battle of those strongest beings in this universe.' Eero smiles intriguingly, while drinking juice, sitting and basking in the sun, also observing Goku's Kaio Ken effect.
In this form, Goku gains the upper hand and forces Vegeta to use one of his signature attacks.
Flying straight up into the air, Vegeta powers up and unleashes his Galick Gun at Goku and the earth. Unable to move for fear of letting the blast hit the earth, Goku charges up to Kaio-ken x3 again and launches his own Kamehameha at Vegeta.
'Such an ineffectual use of Qi,' Eero shook his head.
The two blasts collide intensely, and Goku finally gains the upper hand by stepping up his Kaio-ken to x4. The Kamehameha overpowers Vegeta, who goes flying into the air. However, this leaves Goku's body devastated.
Yajirobe, who had been hiding nearby the entire time, comes out to congratulate Goku, however when Goku says Vegeta is not defeated, he quickly hides again.
Up in the air, Vegeta is enraged that Goku was able to surpass him and decides to transform into a Great Ape; however, he discovers that the moon is gone. He flies back down to the ground and creates a Power Ball, simulating a small moon at the cost of a significant amount of Ki.
Vegeta then transforms into a Great Ape; however, unlike Goku or Gohan, he is able to remain in control of his body. Vegeta states that when a Saiyan transforms into a Great Ape, it multiplies their power ten-fold and thus attacks Goku mercilessly.
"So this is the transformation of Saiyan, but 10 times strength is tasteless in front of Super Saiyan first 50 times and 2nd 100 times, third 200 times, Super Saiyan Blue is 400 times. These Saiyan are really costume-changing race." Eero muttered intriguingly, looking at the huge sane gorilla.
During this time, a shocked Goku has an extended flashback of his adoptive grandfather warning him of a monster outside during a full moon, Kami contemplating cutting his tail off.
Finally remembers himself as a Great Ape destroying both Emperor Pilaf's castle and the stadium at the World Martial Arts Tournament, realizing that he was the one who destroyed both and crushed his grandpa to death.
Goku manages to blind Vegeta with a Solar Flare and then attempts to create a Spirit Bomb; however, Vegeta discovers it and shoots a Mouth Blast at him, causing him to lose most of the Spirit Bomb energy.
Then he crushes Goku's legs, leaving him paralyzed and unable to fight, and proceeds to crush him in his gigantic hands. Gohan and Krillin notice the strange powerful Qi and rushed back to aid Goku.
Upon arriving, Gohan distracts Vegeta while Krillin uses his Destructo Disc to try and cut off Vegeta's tail. Vegeta senses the attack and dodges it.
Yajirobe, however, proves himself to be useful by cutting off Vegeta's tail himself. Vegeta reverts to normal and is obviously upset. Vegeta decides to attack Gohan, but Krillin intervenes and is quickly disposed of.
Goku calls Krillin over to him and tells Gohan to fight Vegeta. Gohan holds his own but is clearly outclassed. Goku hands off the remaining energy he gathered in forming the Spirit Bomb to Krillin, and King Kai tells him telepathically to throw the Spirit Bomb at Vegeta when the moment is right.
Vegeta backs Gohan into a corner, and Krillin is about to throw it; however, Yajirobe yells at Krillin for waiting so long. Vegeta hears this and manages to avoid the Spirit Bomb, and it heads right towards Gohan.