From Dragon Ball Encyclopedia, the ''Dragon Ball'' wiki
Future Trunks performs a series of rapid arm movements before placing his palms forward with the thumbs and index fingers touching each other to form a small diamond shape. He then fires a sphere of energy from his palms towards his opponent. This attack can be used with one hand, as he has demonstrated while using his sword in his other hand.
The History of Trunks
Broly: The Legendary Super Saiyan
Future Trunks used this technique against Broly in Dragon Ball Z: Broly: The Legendary Super Saiyan, but to no avail as Broly was unfazed by the attack and knocked out Future Trunks with a punch to the chin.
Tenkaichi series and other video games
The Burning Attack has been seen in various video games and almost always accompanying Future Trunks, such as Dragon Ball Z: Sūpā Butōden 2 and the Budokai Tenkaichi video game series. Trunks is also seen using this attack to help defeat Hatchiyack in one of the endings of the Saiya-jin Zetsumetsu Keikaku video games, although it is blue in color. Trunks had this attack from the time he was playable in Dragon Ball Z: Buu's Fury, .
Dragon Ball Online
The Burning Attack also made its debut as the first offensive technique performed by Time Patrol Trunks Brief in Dragon Ball Online. When Time Patrol Trunks used the attack in a cinematic cut of the player's tutorial, he performed the traditional series of rapid arm movements and stance, however, the color (blue) and power differ because he performed it in his base form.