Eight-Tailed Ox Menacing Ball

Similar to Naruto Uzumaki's Four-Tailed and Six-Tailed Fox Menacing Ball techniques, after Killer Bee fully transforms into the Eight-Tailed Beast, he gathers vast amounts of chakra at his mouth in the form of a black sphere with electricity, and launches it at his targets as a giant wave. The resulting explosion was enough to devastate the entire Valley of Clouds and Lightning.

Trivia

 * Apparently the jutsu is actually called the "Menacing Ball" and it can be charged with different levels of power.