"Say hello to your doom, Cell!!"
First, Future Trunks throws his opponent up in the air and points both his hands up in the air. Then, he charges a large dome of yellow energy around himself. From this energy dome expels a gigantic Finish Buster up at the opponent, inflicting an enormous amount of damage.
Future Trunks uses this attack to destroy Future Cell in his alternate timeline. Thanks to his training from the present timeline, Future Trunks easily outclasses Future Cell and knocks the Android down into the ground. When Future Cell attempts to attack with his tail, Future Trunks catches it and throws Future Cell up into the air. Future Cell then prepares a Kamehameha in hopes of defeating Future Trunks, but Future Trunks counters and destroys Future Cell with the Heat Dome Attack before he could fire his Kamehameha, declaring that the nightmare is over. With the Androids defeated and peace finally restored in his timeline, Future Trunks thanks Goku and the others for everything they have done for him.
An extremely angered Super Saiyan 2 Vegeta later uses this attack during his battle with the God of Destruction Beerus, however Beerus emerges from the attack completely unscathed. Later in the series during a flashback, it is shown when Future Trunks fights Future Dabura and Future Babidi, he uses a similar technique to the Heat Dome Attack.
Video Game Appearances
Heat Dome Attack is named in the Budokai Tenkaichi series, where it appears as Super Saiyan Future Trunks' (without sword) Ultimate Blast. It also appears in Dragon Ball Z: The Legend, Dragon Ball Z: Burst Limit, the Raging Blast series, Dragon Ball Z: Ultimate Tenkaichi, Dragon Ball: Tap Battle, Dragon Ball Z: Battle of Z, and Dragon Ball Z: Dokkan Battle.
It is also used by Future Trunks in Dragon Ball Z: Shin Budokai - Another Road, Dragon Ball: Zenkai Battle Royale, and Dragon Ball Heroes. In Dragon Ball Heroes, the attack can be combined with two Kamehamehas from Goku and a player avatar; the combined attack is so powerful that it blasts the opponent into space. Additionally, as a Super Saiyan 3, Future Trunks uses the attack against Majin Buu in the second promotional video for Dragon Ball Heroes.
"Trunks' big move. Shoot a huge Ki Wave straight up!"
— Dragon Ball Xenoverse Skill description
In Dragon Ball Xenoverse, it appears as Future Trunks (DBZ Era) and Trunks: Xeno's Ultimate Skill. It can also be obtained by the Future Warrior as a reward in Parallel Quest 26: "Warriors' Annihilation - Future Chapters" which is randomly dropped by Future Trunks when he is defeated during an Ultimate Finish which occurs only if Android 17 and 18 survive. Super Saiyan Trunks' equipable Z-Soul, "Vanish forever!" (based on his final words to Future Cell) increases the power of the Heat Dome Attack and all stats temporarily increase when the Heat Dome Attack is used. This Z-Soul mistakenly refers to the technique as both Destruction Bomb and Heat Dome in its in-game description.
Trunks: Xeno can also use the technique as his Super Attack in Dragon Ball Z: Dokkan Battle.
In Dragon Ball Xenoverse 2, it returns as an Ultimate Skill used by Future Trunks in his Capsule Corp. Clothes 2 and Battle Suit skillsets while Trunks: Xeno uses it in his Long Coat 1, Long Coat 2, and Captain Ginyu (Trunks: Xeno in Ginyu's Body) skillsets. It can also be obtained by the Future Warrior as a reward in Parallel Quest 40: "The Future Warriors!" which is randomly dropped by Future Super Saiyan Future Trunks when he is defeated during an Ultimate Finish which is triggered by completing the quest in under 8 minutes. Though Vanish forever! returns as Future Trunks/Trunks: Xeno's Super Soul it no longer increases Heat Dome Attack's power as it boosts Ki Blast-based skills by an extra large amount temporarily when any Awoken Skill is activated though as Heat Dome Attack is a ki blast-based Ultimate Skill the power of the attack will be increased as long as the effect is active though this applies to all ki blast-based skills and not just Heat Dome Attack.
In Dragon Ball FighterZ, it appears as Future Trunks' Meteor Attack where he grabs the opponent and throws them into the air before firing the Heat Dome Attack.