Michael Fassbender Gushes Over His 'Highly Intelligent' 'X-Men' Co-Star Kodi Smit-McPhee

Magneto and Nightcrawler are spending a lot of time together!

Michael Fassbender and Kodi Smit-McPhee are spending an awful lot of time together – but we’re not complaining!

The two cross the American frontier in Slow West, and are currently in the midst of filming X-Men: Apocalypse. Fassbender will reprise his role as Magneto in the latest installment of the popular franchise, while Smit-McPhee was brought on board as a young Nightcrawler.

“Kodi’s a very easy young man to get on with,” Fassbender tells ET. “He’s highly intelligent, he’s got a strong opinion on many things, including acting. He’s confident in his steps, so it was really easy. I just found him a very interesting man to talk to.”

WATCH: Everything We Know About 'X-Men: Apocalypse' So Far

In Slow West, opening in theaters today, Fassbender stars as Silas, a mysterious traveler who joins 16-year-old Jay (Smit-McPhee) in a cross-country journey in search for the woman he loves.

The movie also stars rumored Star Wars: Rogue One actor Ben Mendelsohn as Payne, an outlaw in pursuit of Jay.

“He's such a phenomenal talent and just so unpredictable,” Fassbender said of Mendelsohn. “You don't know what he's going to do next or what direction he's going to go. […] He's an ultimate pro.”