“'Agatha All Along' Star Joe Locke Explains the Big Billy Maximoff Episode”

To fully capture Billy's complicated story, Schaeffer and Livanos knew they needed an actor who could handle all the magical ups and downs. They recruited early on Heart stopper breakout star Locke, and Schaeffer remembers getting chills during his first chemistry reading with Hahn.

“We did a comedy scene and they had great charisma,” recalls Schaeffer. “He was so charming. And then we did a dramatic scene and it felt like the molecules in space were shifting. He's a very lively, fidgety person, but when it comes to acting in a profound, dramatic moment, he behaves in a way that draws you into him. It was like: This is what we need for the Scarlet Witch's son.”

After Locke got the role, he devoted himself to research. (Billy, also known as Wicca, has a long history in Marvel Comics and is a key member of the Young Avengers.) As a congratulatory gift for taking on the role, Livanos gave Locke a copy of AVENGERS: THE CHILDREN'S CRUSADE (2010), one of them Billy's most iconic storylines that Locke says shaped his portrayal.

“I read all of this and at the same time have the ability and freedom to make the character my own,” he says. “The great thing about the MCU is that it doesn't follow the comics exactly, so you have the freedom to adapt characters. Jac and Mary were really great, and when I had an idea for something, I had great freedom to make Billy my own – and make him mine.”

Episode 6 presented a particular challenge as Locke had to play both Billy Maximoff and William Kaplan. The actor says he approached them as two completely different roles and wanted to explore each boy's similarities and differences.

“I saw William as the lighter side,” he explains. “Billy is a much darker character. It's almost as if William was the teenager of the first five episodes until you see the big change and then the darker Billy comes through. He almost had to put on a front for his parents and be the son they had for 13 years. The teenage part of Billy is this fanboy mask, and underneath Billy is a lot darker.”