With the Maqi he had accumulated, Jin concentrated all of it into the Wall Breaker Lance while he was flying. He knew that he must hit or else this would fail spectacularly that the Grey Bears and maybe even the Seven Cities might laugh at him.
After all, being a Lord of these cities, he had to show that he was this super duper cool master that everyone could rely on. That was his actual side thought but in reality, he had enough of this Fira Dragon and learnt his lesson on why Synthesis World's Virtual Simulation did not wish to have any monster Mechanoids built.
The reason for him to fight alongside Archduke Dyke and clear this simulation and later be the winner of this round seems all the more important to him as a vendetta that he must exact. Even though he knew that the Synthesis World's AI Administration had a small hand in forcing him into such situations, they were definitely not the perpetrators for all these secret creations of Monster Mechanoids.