Crystal Star

The Crystal Star is the seventh and final of the Crystal Stars Mario collects in Paper Mario: The Thousand-Year Door. Originally, the Crystal Star was kept hidden in Rogueport, but Grodus and the X-Nauts found it and took it to their fortress on the moon. After reaching the moon through Grande Boom in Fahr Outpost, then navigating the X-Naut Fortress, Mario and his partners have to fight Lord Crump in the Magnus von Grapple 2.0 mech suit to recover the stolen Crystal Star and pursue Grodus through the Palace of Shadow after TEC tells the heroes what happened before their arrival, noting that Grodus, before shutting down TEC after learning Mario and his team found the real Garnet Star after Beldam, Marilyn and Doopliss were tricked with a fake one, decided to forget about following Mario to obtain the other Stars, considering he would open the Thousand Year Door for him. The Crystal Star teaches Mario the move Supernova upon collecting it.

During the final battle with the Shadow Queen, when the Crystal Stars spread out to the locations as to where they were found, the Star does not return to where it was originally found in Rogueport, but instead retreats to Fahr Outpost, alerting the mayor of the crisis Mario and his team were facing. It is during this time, the mayor and his assistant assemble the Bob-ombs that operated the cannon's firing chambers as a cheering section for the heroes, just before they defeat the evil queen once and for all.

Trivia
Kristallstern Stella Cristallo