Kaminari charges his body with over a million volts of electricity before releasing it indiscriminately around him. The attack has enough power to take down several opponents at once, but can be blocked by any non-conductive object. This actually worked to his allies' advantage when Momo Yaoyorozu and Kyoka Jiro hid underneath an electrically-insulated blanket created by the former, allowing Denki to let loose his full power without harming them. 
Denki usually suffers from short circuiting his brain after using this attack, described as him "becoming an idiot for a while" afterwards, rendering him defenseless and unable to do anything beyond walking around aimlessly while giving two thumbs up. Although during the Cavalry Battle, Denki was able to use the move more than a few times before jamming himself, showing some signs of improvement.