Omega Shenron pushes his chest forward, channeling pure negative energy through the cracked dark-blue Dragon Balls on his chest. Small red streams of energy fly out and start to form a crimson energy sphere as it expands many times its original size. Omega Shenron condenses the sphere to about the size of his body and launches it at the opponent, inflicting a huge amount of damage.
Omega Shenron first uses this attack in an attempt to destroy Super Saiyan 4 Gogeta and the Earth. However, Gogeta teleports in front of the Negative Karma Ball and channels some of his positive energy into it by his knee before he kicks it up into space. This changes the Negative Karma Ball into a positive energy sphere (with a whitish blue color) that soon creates a nuke-like explosion upon leaving the Earth's atmosphere, which removes all traces of the dark clouds covering the Earth along with the negative energy in the air.
Omega Shenron later uses it against the weary Goku and Vegeta, which nearly kills the former. Omega Shenron uses the Negative Karma Ball on Goku again while he is holding the Universal Spirit Bomb, but to no avail until Goku kills Omega Shenron.
Appearances in games
This technique is called Minus Energy Power Ball in Dragon Ball Z: Budokai 3, Dragon Ball Z: Infinite World, Budokai Tenkaichi series, and Dragon Ball Heroes where it appears as Omega Shenron's Ultimate Blast. During the attack, he usually announces "This whole planet... WILL BE DESTROYED!" and causes collateral damage.
In Dragon Ball: Xenoverse, it also appears under the name Minus Energy Power Ball is an ultimate skill used by Omega Shenron. It is also used by Mira when he is fought in the main story and appears his 3rd skillset as part of GT 2 Pack DLC. It can also be obtained by the Future Warrior via a wish from Shenron.
In Dragon Ball Z: Extreme Butōden, Omega Shenron uses the Minus Energy Power Ball as his Z-Assist when he is summoned as a support character. When summoned he will appear and fire the Minus Energy Power Ball diagonally down from the air.