"Great Battle Power" (大戦力, Dai Senryaku) is the 68th chapter of the One-Punch Man manga series.
Hundred-Eyes Octopus defeats several B-Class heroes with ease. The monster attempts to kill Red Muffler, but Bone manages to save his fellow hero. The two then carry the knocked out heroes to safety. Bone attempts to defeat the monster by himself, but is unfortunately crushed by the octopus's tentacle. Death Gatling and other A-Class heroes come to Red Muffler's aid. Before any of the heroes could act, Flashy Flash rushes to attack Hundred-Eyes Octopus.
Flashy Flash proceeds to blind the monster by slicing all of its eyes. The monster squirms in pain, destroying even more infrastructure nearby. Everyone except Flashy Flash retreat and as Flashy Flash is about to finish the monster, suddenly Tatsumaki pulls the monster off of the ground. Tatsumaki crushes the monster into a ball in the air and drops it. Tatsumaki then scolds everyone for not taking care of the monster fast enough. Flashy Flash attempts to defend himself, but is stopped by the other heroes. Gyoro Gyoro and Orochi discuss the revelation of the power of the S-Class. Orochi tells Gyoro Gyoro that it will not be a problem and they can make as many Mysterious Beings as they please.