While most of the Destiny 2 fan base is busy waiting for the launch of the Curse of Osiris DLC to inject new content into the game, some are keeping themselves busy in unique ways. For the most part, the mountain that is the Leviathan Raid was thought conquered, but a few dedicated Destiny 2 players are still finding new ways to challenge themselves. The latest achievement may be the most impressive, if only because it requires a lot of things go right.

This week, a Destiny 2 fireteam of only two players was able to beat the final Calus boss fight in only one phase. Previously, a two-player team was able to beat Calus, but this new team did so much faster.

Compared to that first team, this team (composed of Gladd and Tfue) only did a few things different and used the same basic strategy. They still used the hiding spot in the Shadow Realm and the Throne Room player relied on Wardcliff Coil to take out most of the enemies. That may seem easy, but for the player in the Throne Room it can be tough to stay alive with enemies spawning from all angles and Calus shooting his laser beam.

The real question is how the team is able to beat Calus in one phase. First, it starts with the Shadow Realm player who uses a perfectly timed Rally Barricade and an auto rifle to kill 123 skulls for a huge Force of Will buff. Meanwhile, the Throne Room player is constantly meleeing as many of the Psions as possible to ensure that every damage plate has a Power Ammo brick on it.

Once the damage phase begins, the team starts out with a Rally Barricade and the Curtain Call rocket launcher. They use the Barricade to fire 6 shots from the rocket launcher before switching quickly to Wardcliff Coil and picking up another Power Ammo drop. They do this because even 1 round of Wardcliff Coil ammo can turn into a full “clip” for another rocket launcher. It’s a known glitch with the game, and coincidentally it’s the same glitch that was used by Gladd and his teammates during the World’s First Prestige Mode run.

Even with the glitch, there is a lot about this run that needed to go right to succeed. Without the quick switches between Wardcliff Coil and Curtain Call, the team wouldn’t have had enough DPS. Similarly, the Rally Barricades are an invaluable tool because they allow for firing rockets extremely fast. Some will dismiss the accomplishment because of the use of exploits, but this is a very impressive feat.

Destiny 2 is out now for PC, PS4, and Xbox One.