Kingsman: The Secret Service was an incredible and hilarious spy movie that upended the genre and was almost universally loved at the box office. One of the coolest characters was a villainous double-amputee who just so happen to beat down enemies with her sick moves and prosthetic blades for legs. Meet Gazelle, the right-hand woman to Kingsman's antagonist; played by Sofia Boutella, she's cool, beautiful, and seriously deadly.

With that in mind, we present an exclusive, behind-the-scenes look at how the producers cast Boutella, and what the actress thought about working with Samuel L. Jackson. They talk about what makes Gazelle so compelling, despite being a lethal killer; Boutella admits she isn't "the obvious villain," but how that also drew her to the role. And one producer talks about how he knew Boutella was perfect for the role—it all started with her Nike dancing video.

Check out the clip above—and watch the whole movie again when it comes out to Blu-ray and DVD tomorrow, June 9. Can't wait? Kingsman is available on digital HD now.