The zenkai boost is a pure power boost Saiyans get after taking a a lot of damage and recovering from it, what Vegeta was talking about is something else.
Demiurge
2021-12-09 05:50:49 +0000 UTC
i think it was explained somewhere the reason for that is actually twofold.
first, super saiyan is actually stonger than kaio-ken, without any of the drawbacks. base super saiyan alone is x50 stronger than your base, ssj2 is x2 that and ssj3 x4 that. so super saiyan is actually the better choice if you can only use one of the two. second is that both forms just take a lot of stamina to use, so combining both is just to strainous on the body and would probably kill you. ssj blue is different as it is all about perfect ki control, so the strain on goku's body by it is lessened, meaning he is actually barely able to withstand the extra strain caused by kaoi-ken.
(there's also the theory that he could but never really need to combine the two before. goku only fought 4 times after frieza. against android 19 ssj was more than enough. for cell he always had planned for gohan to be the one to kill him, so there wasn't a reason to try. and for buu .... again he wanted someone else to handle it, gotenks in this case. so there really never was a reason for him to try and make the two work together before.)
JHow
2021-12-06 00:50:30 +0000 UTC
What's the reason for that? Because if it was always available why not use it against Cell or Buu?
Monokuma
2021-12-05 23:12:14 +0000 UTC
not gonna lie, this is a fun throwback episode. seeing the kaio-ken back in action gave me a nice endorphine shot. it was such a cool idea back in the day and i was always a bit sad goku never tried to use it again, so this was a more than welcome surprise.