A stylized D of magic energy is placed on the hand of the intended target and after a certain amount of time it will explode, killing the person and anyone nearby, However it is possible to remove the emblem to prevent this.
Appearance in games
Majin Emblem was named and first appeared in Dragon Ball: Xenoverse. Demigra places his Majin Emblem on the Future Warrior before helping them travel to Age 785 to save Future Trunks from Dark Future Perfect Cell. After the Future Warrior defeats Mira and helps SSJ3 Goku fight Dark Majin Buu, the Emblem starts to glow when the Warrior returns to the Time Nest. Future Trunks notices the Emblem and wonders what it is when the Supreme Kai of Time rushes on to the scene and demands the Warrior to put out their hand. The Supreme Kai of Time removes the Emblem and Seals it in a sphere which she throw into the air and the Emblem detonates. The Supreme Kai of Time reveals that it was a Majin Emblem and before she can explain any further, Demigra arrives and reveals that the Emblem was meant to end their lives painlessly.