Originally Posted by Majuub

Sorry but that's a fanslation which can't be used in a canon debate. That's just a scan taken from that Bleach site.

In my version(French) Vegeto said: Ne t'inquiètes pas, moi-même je suis impressioné par ma puissance''

Literally: ''Don't worry, even I, am suprised by my power''

Vegeto's goal was to get absorbed by Shin Buu in order to free the others. In order to do so, he had to push Shin Buu to absorb him. He played a mind game with him by teasing him and provoking him, that fight was also psychological as Vegeto was slapping him around and was beating him without his hands. He only used his legs. Even when he was turned into a candy he was still winning. The fact he said he was suprised by his power is just another way to tease Buu and use cockiness as a bait to get absorbed. Also, Vegeto is a fusion, even Gotenks said he was impressed by his own power after he did his Buu Buu volley-ball on Shin Buu. Still, it doesn't mean the fusion of Goten and Trunks held any particular increase. It's just sheer boasting.

Goten and Trunks weren't even able to go SSJ2 prior to the fusion, I'm not even sure they're MSSJ's. Even after the fusion they couldn't go SSJ2 or SSJ3, still Gotenks was able to easily access and even hold his SSJ3 state. With that said, if SSJ Goten and Trunks can go SSJ3 while fused, I see no reason for Vegeto to not be able to do the same. Also, Shin Buu knew both could go SSJ2, there is no difference, he still thought their SSJ2
state was no match for them.

Edit: No, Goku never thaught the kids how to go SSJ3, he said they did it just by watching him and he was suprised. Vegeta also saw him go SSJ3 and as Goku is part of Vegeto and he knows SSJ3 and Vegeta knows SSJ2 that completely kills your point. Neither Trunks nor Goten could go SSJ2, now for Vegeto one knows SSJ3 and the other knows SSJ3 and yet they can't go SSJ3 while fused?? Goten and Trunks didn't know the technic to go SSJ3 neither, they just saw it, Vegeta is smarter and a better fighter than them, so if they can copy it while fused, surely he can do the same.