Prolly Gohan, though in that Wrath of the Dragon movie SSJ3 Goku came out on top against Hirudegarn where Gohan and the others couldn't, but that probably doesn't hold too much weight since it was just a movie (and most likely non-canon at that).
I get the impression the main difference is endurance (SSJ3 can only be maintained for so long, Mystic doesn't need any power to keep going), and Mystic doesn't mess with your head and make you as battle-focused as the SSJ modes.
Chou Gohan is the strongest unfused character the DBZ-verse has ever produced and he was manhandling a version of Buu whom Goku was afraid of fighting even with Vegeta's help.
I don't honestly see how this could even be a close fight.
I'll reiterate the endurance difference. SSJ3 could only be held for a relatively short time, Mystic is indefinite, so even if SSJ3 Goku is stronger, he might or might not be able to win in time, and against Mystic, he definitely can't last long enough.
This one is a tough one, but i think Goku ssj3 takes this one. Goku has more knowledge when it comes to fighting and did you see the fight that Goku did with kid buu... COME ON!
Pretty sure it was implied that even regular Super Buu was stronger than Kid Buu. Just that Kid Buu was more dangerous because of his increasingly destructive behavior without the goodness of the Kais inside him.
Regular Super Buu isn't stronger than Kid Buu. I also believe its a myth that even Gohan Buu ie stronger than Kid Buu when all in all, it isn't true. Goku withstood a thrashing from Gohan Buu and him and Vegeta was beaten to a pulp by him. By the time Goku made it to the Ki planet to face Kid Buu, his powers increased to high levels due to him healing after the major damage he withstood before facing Kid Buu which is the reason he was able to fight on even footing against Kid Buu.
I think hes basing it on when goku said that him and vegeta would be killed if they left buus body and fought superbuu. I see where he is coming from but I see kid buu as being>superbuu both from his fight with vegeta and ssj3 goku, and that goku and vegeta were noticing that buus power was increasing while he turned back to kidbuu.
Mystic Gohan wins this. Mystic or "chou" Gohan is the strongest unfused character in DBZ. A better fight would be Goku after the ten years are up (when he fights uub) vs Super Buu. The zenkai power up I believe it is called (the one where they get stronger after being beaten up) became inconsequential later on in the series, especially by the buu saga. Super buu > kid buu. They were worried about kid because he is a crazy mo fo and unpredictable. If I remember right, at one point Goku actually wanted to go get Gohan to fight buu instead of him and vegeta combined.
False.
Kid Buu is the most dangerous form because of his reckless nature.
But that doesn't necessarily mean it is his strongest form.
It is his base form, meaning it is his 2nd weakest form (Fat Buu was the weakest).
Buuhan is the strongest Buu version, which was easily toyed around by SSJ1 Vegetto (who is widely believed to be the strongest character in the DB saga, sans the non-canon GT).
False again.
SSJ3 Goku loses
Toriyama has said that Mystic Gohan was the strongest unfused character in the DB saga.
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