S1·E12 Heaven and Earth Shock, Big Spirits

While Masaomi and Kibachiyo fight Yakumo and (one of) his Shikigami, Seiryuu no Buryune, Riku and Kogenta battle Yuuma and Rangetsu. When all else fails, Riku decides to use the In that Kogenta taught him before: Hundred Ghost Obliteration Attack. But something strange happens to Kogenta after Riku uses it...