Vegeta needs to use a power that greatly exceeds Kaioshin's own power for Kaioshin to be impressed since Kaioshin already expects them to be more powerful than himself.
Come to think of it, he was hard to hold back. He doesn’t seem to remember sending him all too well, also Kaioshins ki sensing seems wacky. But watching an actual fight is easy.
Kaioshin seems to reveal that he didn’t full sense his power later in the ship. Also he didn’t witness Gohans speed, whereas he fully witnessed what Vegeta could do.
This idea is proven false by the Buu Saga and Super though. That's the entire reason we are discussing this. We had some indirect implications of his strength that get overruled in later sagas.
Negative, we are unaware of their base powers. Last we saw Base Trunks was able to kiai Imperfect Cell completely out of the city.
The Base powers of the MSSJ fighters is an unknown. We know it's unlikely for Piccolo to be anywhere close to even 50% Goku most likely since a variety of powers...
Nothing suggests any of that would be necessary for someone like Piccolo. They don't even need to do that for Kaioshin, why would they do it for Piccolo?
Do you really think Gohan is asking Vegeta to lose when he's asking him to fight in Base? Why wouldn't Vegeta object completely? He is taken aback, but then goes on to say his advantage remains the same and he will win the tournament.
Base Vegeta > All is stated right there. Vegeta knows...
He'd rather RISK losing to Kibito. He doesn't think Kibito is going to beat him, just that he might be a tough competitor, and he can't hold back in a way not to be superhuman. So we know Super Saiyan was never a factor in his thinking. So he cannot be confident in winning the tournament in Base...
He knows exactly how strong Pui Pui is though.
Giving up energy is not possible unless Badibi's men are threats. Would Kaioshin worry about giving up energy to Raditz?
Because despite Goku being ok to fight Yakkon, it's still a disadvantage to be fighting in the dark. If there's a choice, they...