I couldn't imagine how you could defeat a being described in RPG terms as "the secret boss stronger than the final boss", but seeing that, it made a lot of sense to me.

Nasu: Monsters are monsters because humans can't beat them. That thought begs the question: "What about Camazotz, who defeated ORT once?", but well, he's just a tremendous guy (laughs).

I'm curious to know how he did it.

Nasu: It was just a simple physical rushdown after every citizen and Natural Spirit invested their powers into giving him an unperishable body. The basic idea to keep attacking forever because they had no means to defeat him on a permanent basis. Camazotz favored spears, so his final move was a focused stab to the core at the center of the UFO, done through full-power flight. He was almost erased in the process, with his legs, torso, and head pulverized, but only the right hand gripping the spear survived, thus ORT's flying saucer fell to the Xibalba ground. I requested his "One point, focus only on one point!" voice line in his boss battle to be a recreation of that. ORT's coffin was made from the craters of Camazotz's spear attacks. That was where ORT's carcass dropped, so the coffin interior that the player sees once used to be ORT's crust.

That was an amazing story.

Nasu: Camazotz's spear and the right arm gripping it were left behind in Xibalba. Camazotz can't die, so he eventually regenerated from the arm, but in the time it took until he did, Malla collected the heart that Camazotz gouged off with his final will and made it the source of the sun. That's the general sequence of events.

Nasu and Takeuchi's 8th Anniversary interview, part 2 (on U-Olga, Daybit, and ORT)