WHAT DID KRILLIN TEACH 18? π€
Many doubt that Krillin trained during the 7 year time skip between the Cell & Buu saga, but Krillin DID do some training for a few of those years & even trained with 18. What did 18 learn from Krillin?
How to control her energy output.
How to sense ki signatures.
How to form a Kienzan.
Most of this is implied information from Toriyama's work. Although it's not openly said that Krillin taught 18 all if this, we can find evidence of this to be true if we look close enough & use proper context.
β’ Suppressing Her Energy Output:
18 has been show to have a difficult time suppressing her unnatural power. When 18 barely tapped the punch-machine, it showed how much she still lacks control when barely putting energy out for a simple attack.
Krillin reminds 18 to not punch too hard & 18 expresses that it's hard to control her power. That implies that Krillin was helping 18 to control & supress her energy output at some point during the 7 year timeskip. Krillin would only know that from training with 18, then teaching her to control her energy.
At the very least, Krillin helped 18 control & suppress her energy output before Marron was born & again after Gohan informed them about the 25th Tenkaichi Budokai. 18 can easily be gentle with her daughter, but the issue is controlling her unnatural power when she attacks.
β’ How To Sense Ki:
In the Cell saga, #18 could not detect ki. #16 was the only one equipped with sensors to detect energy. But, since 18's still human, it's possible for her to learn how to sense ki.
So, after Cell was defeated, Krillin taught 18 how to sense ki. Where's the proof?π
When "Mighty Mask" transformed into a Super Saiyan, 18 was unable to see the SSJ hair of Goten & Trunks since they were covered up. BUT, because SSJ radiates a unique ki signature, 18 sensed it.
We have been shown prior that SSJ has a unique type of ki signature that can be distinguished from other energies.
Then, there's this incident after Majin Vegeta destroyed part of the audience & 18 sensed that something was very off with his ki. (This is scene anime only, but still consistent with her being able to sense ki.)
And the most important piece of evidence comes from "Yo! Son Goku And His Friends Return!" where 18 blatantly says that she can sense ki.
I'd say that there is enough indisputable evidence to prove that Krillin UNDOUBTEDLY taught 18 how to sense ki. Krillin even taught her well enough to distinguish regular ki from SSJ ki. But, more than likely, 18 is still not a master at sensing ki.
β’ The Destructo Disk:
This one is obvious. However, it's important to note that 18 never used this technique in the Cell saga. This means that unlike Cell, 18 WAS NOT programmed with the ability to use the techniques of Krillin & other fighters.
Although Dr. Gero programmed combat info into his androids and cyborgs, he did not have an understanding of how ki works. So, as a replacement for ki, Gero gave his creations artificial energy to replicate ki (as well as equipping certain androids & himself with energy sensors). This is why 18 never used the Kamehameha, Solar Flare, or any other technique. The twins only fire energy blasts. And unlike 17 who can generate a barrier, 18 is never shown have the ability to produce a shield in canon (18 only has that ability in certain video games).
18 may not have certain built-in abilities that 17 has since Gero nerfed her power in comparison to her brother in order to see if he could control them easier. But, that does not mean she is incapable of creating a barrier. It could simply be that 18 doesn't know how to create a barrier yet, or she chooses not to use the barrier for whatever reason. Until 18 uses a barrier in the main story, I cannot claim for a fact that 18 has a barrier.
18 just isn't very adept & skillful with energy control besides using what is essentually "built-in energy guns." She could already generate artificial energy with ease, BUT when 18 learned the Kienzan from Krillin, she needed to learn how to control it, shape it, and weild it properly. It very well could've taken her a bit of time to learn this from Krillin. A normal Earthling that was granted super-human power WOULD NOT automatically have knowledge of energy control. Simply put, 18 has the power, but lacks the understanding of how to control said power. Thus, Krillin helped 18 control her energy output & taught her how to manipulate her artificial energy.
Can you tell me a technique that 18 created on her own? Exactly. She doesn't do that. All 18 did was shoot artificial energy because she didn't understand how to manipulate ki. Krillin's Kienzan is literally the only move that we've seen 18 use besides regular energy blasts.
β’ Increasing Her Energy Output:
Prior to the Tournament of Power, 18 trained with Krillin for countless hours & learned how to control her energy more and more.
When 18 was captured by Brianne de Chatteau during the Tournament of Power, 18's love for Krillin (& their daughter) gave her the strength she needed to power-up past her current known limit (similar to a rage boost, but derived much more from love). And although it was temporary, 18 produced an aura for the first time ever! Doing so greatly increased 18's strength, allowing her to take down the gigantic powered-up Ribrianne. It was all thanks to 18's close bond to Krillin & her training with him which allowed her to increase her ki & surpass her limits.
So, there you have it!
UNDENIABLE PROOF that Krillin trained with 18 & taught her things like how to sense ki & how to control her energy.
Need help imagining the training Krillin & 18 did? It's similar to when Gohan taught Videl how to use ki. Just replace Gohan with Krillin (someone more adept with ki) and replace Videl with Android 18 (someone who has artificial energy, but is still untrained in energy control).
