The Saiyan arc marks a crucial turning point for the Dragon Ball series, not only due to the revelation that Goku is actually a Saiyan and not from Earth but because Goku ends up dying shortly after the saga begins. But in a rare change of pace, death is not the end for Goku like it was for Krillin or Master Roshi. Rather, it’s an opportunity to train.
Training with Kaio in the afterlife, Goku manages to learn the Kaioken– a technique that multiplies his strength at the risk of totaling his body in the process. The Kaioken is one of Goku’s most intense and dangerous techniques in Dragon Ball– only used when the situation is indispensable.
- Goku Versus Jiren
Interestingly, both the anime and manga feature Goku using the Kaioken against Jiren– and under incredibly diverse contexts. In the anime, Kaioken is simply a part of Goku’s Super Saiyan Blue Kaioken (which he has more or less fully mastered at this point.) In the manga, however, Goku uses Kaioken as a last resort. Thinking that raw power is the key to defeating Jiren, Goku throws Kaioken on top of his Mastered Super Saiyan Blue, throttling his body for a loss. Master Roshi has to step in and scop his student, reteaching Goku basics he’d forgotten throughout Dragon Ball Super. Taking this to heart and looking back on the masters who defined him, Goku throws away the raw strength of Kaioken and taps into the zen of Ultra Instinct.
2. Goku Versus Hit
Speaking of the Universe 6 Tournament is arguably when Dragon Ball Super starts to find its voice. The tone is explicitly lighter (although with stakes) and the action is somewhere between early Dragon Ball and the Z-era. In the manga, Goku overpowers Hit with Super Saiyan Blue alone, but he needs help in the anime.
Betting his life on a technique he hadn’t used in almost two decades, Goku mixes Kaioken with Super Saiyan Blue, giving him access to Super Saiyan Blue Kaioken. SSBK is more than enough to compete with Hit, but Goku ends up forfeiting the match when he realizes that Hit can’t fight back fully in a tournament setting.
3. Goku Versus Zamasu
Although Goku regains access to the Kaioken in the Universe 6 Tournament arc, it’s not a skill he can use casually anymore. Kaioken mixed with Super Saiyan Blue places too much stress on his body than before (evidenced by a slice of life episode in the anime.) As a result, Goku doesn’t use Kaioken much in the Goku Black arc.
But all that does is end up saving the technique for an impactful moment. With no one left to stand up against Merged Zamasu, Goku does everything he can to fight off the fused fighter. When caught up close by Merged Zamasu, Goku puts everything he has into one Super Saiyan Blue Kaioken charged strike. Unfortunately, there’s only so much a Saiyan can do against an immortal god.
4. Goku Versus Paikuhan
Goku versus Frieza might mark the end of the Kaioken in the manga, but not for the Dragon Ball Z anime. Kaioken makes one more appearance before all is said and done. During the anime’s filler arc following the Cell Games, Goku participates in an afterlife tournament held by the galaxy’s Kaio.
Goku ends up fighting Paikuhan during the course of the tournament– a Piccolo analog– who pushes Goku so far that he ends up mixing Kaioken with Super Saiyan. This is the first incident where Goku mixes the two techniques together, and it would notably return during the anime adaptation of Dragon Ball Super.
5. Goku Versus Captain Ginyu
Captain Ginyu completely outshines the rest of the Ginyu Force. He’s truly in a league of his own, forcing Goku to use the Kaioken barely to be in the fight. That said, Goku very quickly proves himself Ginyu’s superior. The Kaioken is more than enough to put Ginyu in his place, but this ends up being a double-edge sword.
Ginyu seizes the opportunity and switches bodies with Goku. Goku is left in Ginyu’s now half-dead body while Ginyu sets off to kill Gohan, Krillin, & Vegeta. Unfortunately, Ginyu has no clue how to use the Kaioken so he’s much weaker than he should be.
6. Goku Versus Frieza
Goku’s fight against Frieza is the last time he needs to use Kaioken to augment his strength in the manga (effectively replacing it with the less strenuous Super Saiyan,) but is it ever a great exit for the technique. Frieza pushes Goku to his absolute limits, more than Vegeta could. This time around, however, Goku is clearly in his best form.
There’s a ray of hope throughout the battle that Goku can actually overwhelm Frieza, but it’s struck down by the dual revelation that Frieza is only using half his power and Goku has been using x20 Kaioken the entire time. Super Saiyan was a miracle and a half.
7. Goku Versus Butta & Jeice
Goku lands on Namek with just enough time to save Gohan, Krillin, and Vegeta from a grisly death at the hands of Reacoom. Goku’s intense outer space training sessions have increased his strength and power significantly– using biological near-death power boosts to get stronger. Goku doesn’t even need the Kaioken to defeat Reacoom.
In theory, he probably wouldn’t need it against Butta either if it weren’t for his trademark speed. Goku uses the Kaioken primarily to match his speed to Butta’s, but he’s otherwise in his base state during the action. Or so it seems.
8. Goku Versus Nappa
It’s essential to clarify that the Kaioken is a technique, not a transformation. While it’s often treated as an early Super Saiyan analog in the video games, this is far from the case and the Dragon Ball manga is conscious of what Kaioken does to Goku’s body. The point being: the very first time Goku used the Kaioken.
Goku had actually been hoping to save the Kaioken against Vegeta, but he ends up triggering the technique to cut the distance between him & Nappa while immediately subduing his rival. Kaioken makes short work out of a character who brought the entire Dragon Team to the brink of annihilation.
9. Goku Versus Vegeta
Goku actually attempts to fight Vegeta without the use of Kaioken, but the Elite Saiyan’s might is enough to immediately overpower Goku. Where Goku used Kaioken skillfully against Nappa, he’s forced to almost use it as a proper state while fighting Vegeta. Kaioken brings Goku close to Vegeta’s level, but he’s still playing with fire here.
This is most evident during their beam struggle. Goku pushes Kaioken to x4, which overwhelms Vegeta, but at the expense of his own Ki. Vegeta still has enough energy to fight another battle if he wanted to (and he ultimately does.) Goku, on the other hand, is completely wiped from putting so much stress on his body.