The Key Sword appears to be a golden blade consisting of a long handle and several gear-like parts, a red gem within a gear acting as a pommel, and a small golden spike protruding from the top of a semi-gear. It appears that it must be worn like a gauntlet.
The Key Sword was created by the gods as a weapon to seal demons, it gives its user some resistance to the attacks of a demon.
In the manga, Robelu transforms Xeno Trunks' sword into the Key Sword so that he can use it to keep the hell gates open. When faced with the brainwashed Time Power Unleashed Chronoa, Xeno Trunks transforms into Super Saiyan 3 and uses this sword to defeat her.
- Key Sword (Full Charge version) – The Key Sword wielded by Super Saiyan God Xeno Trunks. After being fully charged by Chronoa, Tokitoki, and Demigra with the powers of light, darkness, gods and time, its color becomes crystal blue and the front blade is extended to form a true blade, in addition to the front design forming a complete gear and extending into a sort of crossguard. Crystal blue chains additionally wrap around Trunks' arm to secure his grip. In this state, the Key Sword is powerful enough to seal Mechikabura's Time Power Unleashed form.
Video Game Appearances
The Key Sword appears as an item during the missions of the Dark Demon Realm Saga in Dragon Ball Heroes, where it is used by the Time Patrol to seal the Hell Gates opened by Towa in the Hell Gate Assault Saga. It later reappears as an item during the missions of the Dark King Mechikabura Saga, where each member of the Time Patrol-Demigra Army alliance is given one by Demigra to close the Hell Gates protecting Mechikabura's Tower.
Xeno Trunks uses his fully-charged Key Sword to seal Mechikabura's youth, weakening him enough for Chronoa to seal him away.