It doesn’t take much to phase Seana McKenna, but the acclaimed Canadian theatre actress admits the thought of playing a maniacal serial killer had her a bit rattled.

McKenna is tackling the title role in Shakespeare’s Richard III this spring at the Stratford Shakespeare Festival where she will ask audiences to look past her sex and see a paranoid and power- hungry king.

“Before I started, I was terrified because we were challenging a lot of preconceptions,” says McKenna.

Taking on the role of the ruthless monarch — not to mention one of Shakespeare’s most text-heavy roles — has become less daunting for the Toronto-born actress now that she’s inhabited the character for several weeks in eight-hour-a-day rehearsals.

McKenna says the initial hurdle to finding “her” Richard was figuring out how she would tackle him physically.

“I looked at how to shift the bumps in my body — how to pare down my femaleness and accentuate my maleness,” McKenna says. “I will be playing him as a male, but he will be a strange male.”

Renowned for heavyweight theatrical roles, McKenna has performed two one-woman shows within the past year — as Joan Didion grieving her husband’s sudden death in the American writer’s memoir The Year of Magical Thinking and as Shakespeare’s other half Anne Hathaway in Shakespeare’s Will. (McKenna will be reprising Shakespeare’s Will at Stratford this season).

Then there’s the vast array of classical characters McKenna has performed in her career, spanning more than 30 years, including Medea, Phèdre, Lady Macbeth and Cleopatra.

At 54, McKenna says taking on the role of Richard means playing a character that matches her age and experience, which isn’t too common for women in the world of classical repertoire.

“The most demanding roles are often when you’re younger — the Juliets and the Rosalinds. With men, they’re playing Lear after around 60 years of experience.”

McKenna says it’s also been refreshing to inhabit a role that lacks any form of human compassion.

“Women are often the emotional vessels in Shakepeare’s plays, so it’s nice to be plotting and calculating and doing no good.”

And, gender aside, McKenna says it’s pure fun playing a villain.

“I’m going to play him as an imposter,” McKenna says. “This man has no soul. He’s playing many parts, and he’s lying with the sheer bravura of just doing it.”

For someone so used to playing the meaty roles at Stratford and in theatres across Canada and in the U.S., McKenna’s childhood sounds settled. She grew up in Etobicoke with her Irish-born father, a businessman, and her mother, who stayed at home to look after her and a younger brother.

At an early age McKenna gravitated toward the theatre. She says she was a quiet child who loved books and literature.

“The theatre seemed to bring these worlds to life,” she says.

McKenna studied for a year at the University of Toronto before leaving for the National Theatre School of Canada in Montreal.

“I thought I’d try it out for a year,” she says. “I thought, ‘If I keep getting work, I’ll continue.’”

A key to her success was accepting every job she was offered out of school, McKenna says.

“I find in the theatre one job leads to another.”

She also saw acting as a way to travel across Canada since the lifestyle can be nomadic.

In the early ’80s, McKenna made Toronto her base and threw herself into the thriving alternative theatre scene at Theatre Passe Muraille and the Toronto Free Theatre (now Canadian Stage).

She eventually was accepted into the Young Company at the Stratford Festival, beginning a relationship that has lasted 19 seasons.

Although McKenna insists she “lives and breathes” easier onstage, she has shown herself to be comfortable in front of the camera as well. McKenna’s work in the British Canadian film The Hanging Garden (1997) — as a mother attempting to “cure” her homosexual son — won her a Genie Award.

But while many actors hold off on theatre work to be available for film and TV roles, McKenna has chosen to do the opposite.

She lives outside of Stratford, Ont., with her husband, theatre director Miles Potter, and their 13- year-old son, Callan.

Potter, who directs McKenna in Richard III and Shakespeare’s Will, has been a great mentor throughout her career, she says.

McKenna says life as an actor is always a hustle, so it’s important to remember why you entered it in the first place.

“If you remember why you love it, it will keep bitterness at bay,” McKenna says. “It’s not an easy life — the best person isn’t always cast — but you can’t take it personally. You’ve got to keep the delight and surprise in your eyes.”