In Dragon Ball Z episode 190 , " The Horror Won't End ," a vastly more powerful "Super Perfect" Cell returns, threatening to destroy the solar system with a massive Solar Kamehameha, which causes a despondent, one-armed Gohan to lose hope, as he believes he has failed his father and the Earth.. Just as despair sets in, Goku delivers a telepathic, motivational speech from the afterlife, inspiring Gohan to prepare for a final, one-handed Kamehameha clash, culminating in one of the most emotional moments in the series. You can find detailed information about the episode on the Dragon Ball Wiki and Kanzenshuu .