First, Vegeta launches a Super Big Bang Attack, but the enemy dodges it, and Future Trunks appears from the sky and uses his Rapid Sword Stream attack, slicing the opponent to bits, then Vegeta launches a Final Flash, finishing the enemy.
It was first used in Trunks' story in the game, when Future Trunks and Vegeta saw Broly traveling with his father Paragus, seeking revenge. Future Trunks and Vegeta knew they had no chance, so they used the Garlic Buster attack to blast Broly and Paragus away.
When Super Saiyan 3 Gotenks is in the team, Trunks appears and a different, more powerful attack is done by the three of them. Vegeta uses the Final Flash, and Future Trunks uses Buster Cannon, knocking the enemy back; however, the foe is still able to block the attack. Trunks then appears, standing next to his father and "older brother," adding his Double Buster to theirs, breaking through the enemy's guard.