DANAI Gurira is already well known to genre fans as the sword-wielding zombie decapitator Michonne in TV’s The Walking Dead. She’s about to be become even better known as royal warrior Okoye in Black Panther, the Afrocentric new Disney/Marvel Studios movie which is set to do some mind-splitting of its own this weekend. Backed by powerful buzz for its blockbuster depiction of Black valour and culture, the film is on track to topple cinematic stereotypes about race and gender — and also February box office records, with a North American opening expected between $145 million and $170 million (U.S.). Black Panther is the first major superhero movie starring an almost entirely Black cast, many of them women in key roles. It’s co-written and…