Originally posted by Endless Mike
Possibly.... however considering that he was rather drunk with his own ego at the time, and there was only one mention of something like that in the entire manga it's unlikely.Compare this to 3 mentions of planet destruction in YYH, 2 instances of dimension shaking, and at least 2 of the planet quotes were made by reliable characters who had no reason to lie or exaggerate and knew what they were talking about (Koenma and Genkai).
But even Koenma and Genkai quotes didn't make them sound like they could destroy the planet with a ki blast or something. They said the planet will be destroyed, but that could be that she and Koenma mean they would take over the planet, since there's only humans on Earth, and no demons that could stop them; even looking at the images they displayed, it only showed demons taking over the planet causing cities to crumble, if they really did mean them destroying planets, they would have showed the planet blowing up, instead of just cities. And we still have to look at their own showings, when Yusuke fire a Rai Gun, it's only shown making an explosion and blowing up hills, if that's all he's capable of doing with his attacks, then I don't really think he have planet destroying power.