"ZENKAI-BOOSTS" EXPLAINED
Saiyans have an innate ability that helps them get stronger during & after combat. I categorize them as "Zenkai-Boosts" & "Saiyan-Power." In this post, we'll look at how Zenkai Boosts function based off of what the series has shown us.
For more about Saiyan-Power, here's this link.
Saiyans have an innate ability that helps them get stronger during & after combat. I categorize them as "Saiyan-Power" & "Zenkai-Boosts." In
HOW ZENKAI-BOOSTS FUNCTION:
Zenkai-Boost are a way for a Saiyan to quickly increase in power after recovering from combat so that they reach their full potential. That potential varies for all Saiyans & most Saiyans were weaker than Raditz. But, once a Saiyan reaches their physical limit and push themselves past that point, a Saiyan will transform into a Super Saiyan IF they are strong enough and IF they capable of the transformation (& nearly every Saiyan was incapable of turning Super Saiyan). Most Saiyans could only turn into an Oozaru during a full moon. And very few knew how to increase their battle power on command (like the Saiyan Elite Nappa & the Super Elite Vegeta).
It's also important to mention that Vegeta surpassed his father while he was still a child and that Saiyans weren't even supposed to capable of reaching the level of power that Namek Saga Goku (who was trained by "low-tier" gods) & Namek Saga Vegeta (who is a Super Elite prodigy).
ZENKAI-BOOSTS ARE LIMITED:
The series has never stated nor shown that Zenkai-Boosts are infinite. On the contrary, the opposite is revealed within the series.
Zenkai-Boosts appear to apply for every Saiyan form. Each form can be pushed to their limit by Zenkai-Boosts until the Saiyan can no longer acquire a Zenkai Boost in those forms anymore. The current Saiyan transformation limit for Goku & Vegeta is Super Saiyan Blue with there currently being no Saiyan transformation beyond Blue. Both the anime & manga have relayed to us that Goku & Vegeta have reached their Zenkai-Boost limit for SSB.
In a similar way, Vegeta reached his Super Saiyan transformation limit with SSJ2 before he learned god ki. However, he did manage to get his SSJ2 form to surpass Goku's SSJ3 form (which was Goku's transformation limit before he learned god ki). But... how do Goku & Vegeta surpass their Super Saiyan Blue limit without Zenkai-Boosts?
Goku uses Kai-o-Ken on top of Super Saiyan Blue. (DBS anime continuity)
Vegeta evolved the power of Super Saiyan Blue. (DBS anime continuity)
(SSBKK & SSBE are different in the DBS manga continuity.)
However, both SSBKK & SSBE are still Super Saiyan Blue. All they did was find ways to amplify the power of their highest transformation through a technique or through evolution.
The other way for Goku & Vegeta to surpass their Super Saiyan transformation limit was to use non-Saiyan transformations that are techniques of the gods;
Goku uses Ultra Instinct (anime & manga)
Vegeta uses Ultra Ego (manga exclusive)
Another way for Saiyans to surpass their limits is through Saiyan-Power; the Saiyan ability to get stronger during combat. But, this is not a process that quickly grants a huge leap in power.
WHO STILL GET ZENKAI-BOOSTS? 🤔
DO GOKU & VEGETA STILL GET ZENKAI-BOOSTS?
From what we are shown, they do not get them anymore after they pushed Super Saiyan Blue to it's limit. They now have to level up like how Earthlings and Piccolo do by having better control if their ki in order to increase their strength. So, back to basics in a way for Goku. Having further mastery of your ki to increase your strength is something Vegeta has realized is necessary in DBS: Super Hero since he has reached a wall he cannot overcome (this differs in the DBS manga continuity quite a bit).
However, Goku & Vegeta still have their "Saiyan-Power" ability (the ability to get stronger during combat) to get themselves stronger when they spar against each other or are in serious fights.
DOES GOHAN STILL GET ZENKAI-BOOSTS?
Regarding Gohan's Super Saiyan forms and his Ultimate form, he cannot get Zenkai-Boosts anymore. He has to rely on ki control in order to get stronger as well as his Saiyan-Power ability. However, Gohan can get Zenkai-Boosts while in his Beast form. He just hasn't faced anyone who can injure him in that form.
Similar can be said of Future Trunks with his Super Saiyan Rage form from the DBS Anime Continuity. Those forms can still get stronger from Zenkai-Boosts & such was shown for Super Saiyan Rage Trunks when he fought Goku Black & Zamasu.
DO TRUNKS & GOTEN STILL GET ZENKAI-BOOSTS?
Yes, but they aren't really fighters nor are they proper martial artists. However, their SSJ form can eventually get pushed to the next transformation with enough Zenkai-Boosts & an emotional trigger. But, as shown with Vegeta, SSJ2 may be the highest form that they can get (without god ki). SSJ3 was only attained by Goku when training with a spirit body in Other World and by Gotenks through magic from Metamorian Fusion. So, SSJ3 is possible for them. But, Goten & Trunks individually haven't even gotten SSJ2 yet after 10 years.
Although Present Trunks & Goten have more potential than Goku & Vegeta, they don't have the same potential Gohan has. And like Gohan, they aren't obsessed with fighting like Goku & Vegeta are. They could be capable of a unique SSJ transformation like Future Trunks' Super Saiyan Rage, but they don't have any drive to get stronger nor anything drastic to push them to get stronger.
DOES BROLY STILL GET ZENKAI-BOOSTS?
Possibly. But, since he awakened his full potential with his Full Power Super Saiyan form (Legendary SSJ), he may not get Zenkai-Boosts anymore or only has a few more left that he can get. I believe Broly's Zenkai-Boosts won't aid him much if any since his "Saiyan-Power" ability already brought out his potential without needing a Zenkai-Boost to do so. Due to Broly being born as an amazingly powerful mutant amongst the Saiyan race, his inborn Saiyan-Power ability is FAR beyond what even a natural born prodigy like Vegeta can do.
While Vegeta & Goku required the use of god ki to reach their current level of power, Broly did not need to do so & was on par with their Super Saiyan God forms within minutes before he even turned into a normal Super Saiyan. Broly's "Saiyan-Power" ability is beyond insane.
DO CABBA, CAULIFLA, & KALE STILL GET ZENKAI-BOOSTS?
More than likely. Although, SSJ2 was the max for the prodigy Vegeta. In the DBS Manga Continuity, Cabba & Caulifla haven't reached SSJ2 yet. But in the DBS Anime Continuity, Cabba & Caulifla may have maxed out with Zenkai-Boosts at SSJ2 despite Caulifla wanting to reach SSJ3. Then again, Universe 6 Saiyans appear to have more potential than Universe 7 Saiyans, so they may be able to reach SSJ3 or some other form.
Regarding Kale in both continuities, she may not have a need for Zenkai-Boosts anymore with her own unique SSJ form. If she can still get Zenkai-Boosts, she probably doesn't have many left.
DO PAN & BRA STILL GET ZENKAI-BOOSTS?
Of course! Pan is 1/4 Saiyan, but still has Saiyan abilities & practices martial arts. Bra is 1/2 Saiyan, but we don't know if she will become a combatant in the main timeline or not. We just saw her as a kid cheering Pan on at the End of Z & she wasn't a combatant in GT. Bra might end up like her Uncle Tarble and just not be a fighter. Who knows. All I know is that they have the Zenkai-Boost ability due to having enough Saiyan blood in them.
According to the video game Dragon Ball Online that Toriyama helped create, future descendants of Goku & Vegeta lost their Saiyan abilities due to having so little Saiyan blood. They were mostly Earthling at that point. And they were only able to access their Saiyan abilities by making a wish to Shenron to unlock their abilities. Toriyama has repurposed some ideas from DBO like the Freeza Force returning when Goku & Vegeta are gone, a new Red Ribbon Army resurfacing, & Tien creating a dojo. So, if Toriyama wishes to use that idea about descendants of Saiyans that he had for DBO & implement it for the main continuity, future descendants of Goku & Vegeta won't be able to use Saiyan abilities (Zenkai-Boosts, Saiyan-Power, Super Saiyan) unless they have that power unlocked for them. However, the GT continuity differs as shown with Goku Jr. & Vegeta Jr being able to turn SSJ rather easily & without having the ability to transform unlocked for them. But, this is nothing new for GT. It has taken liberties with a many other things that end up contradicting Toriyama's established ideas.
➕ EXTRA ABOUT ZENKAI-BOOSTS:
I DO NOT believe that Saiyans get Zenkai-Boosts that put them on par with the stronger opponent they face or an opponent they sense as some ppl believe (99.9% of Saiyans couldn't even sense ki). If this was the case, Vegeta would have recovered and immediately been on par with #18 without training for a year in the RoSaT to acquire a power beyond SSJ. Or Vegeta would've been on par with Perfect Cell after eating a senzu, or even on par with Beerus after being defeated by him.
Pertaining Goku, he would have been on par with Final Form Freeza when he was recovering in a Healing Chamber while the others fought Freeza. However, Goku wasn't even on the same level of power as Freeza even with the Kaio-Ken ×20 & Freeza was holding back. There are too many flaws in that theory for it to be a solid explanation.
I simply believe that Saiyans gradually increase in strength as they fight (Saiyan-Power) while also drastically increasing in strength after near death (Zenkai-Boosts). A prolonged fight gets a Saiyan closer to the level of a stronger opponent while healing after defeat increases their power even more. And there is no garuntee they will be on par with their opponent unless their opponent is slightly stronger than themselves like Vegeta vs Zarbon Round 2. However, as I mentioned before, these Zenkai-Boosts keep happening until they hit their limit. And that limit varies depending on the Saiyan. However, Saiyan-Power comes into play to help push a Saiyan to their limit, then slowly beyond said limit in order to get them to transform IF they are capable of a form higher than Oozaru. And as stated prior, majority of Saiyans were not capable of such.
