* Actor Availability: Alan Cumming, who played Nightcrawler in X2, was not available to reprise his role due to scheduling conflicts.
* Script and Story Direction: The film's writers and director decided to focus on a smaller cast of characters and a more streamlined storyline, which didn't leave room for Nightcrawler's character arc.
* Character Development: Nightcrawler had a significant role in X2, so the filmmakers felt they had told his story sufficiently for the time being.
It's important to note that the absence of Nightcrawler in The Last Stand was a source of disappointment for many fans, who saw him as a popular and beloved character. However, he was later brought back for X-Men: First Class (2011) and subsequent films.