Elarica Johnson: Elarica Johnson. Actress: Harry Potter and the Half-Blood Prince. Elarica Johnson was born in London, England. A British Actress, known for Harry Potter and the Half-Blood Prince (2009), Blade Runner 2049 (2017) A Discovery of Witches (2018) and P-Valley US series with Starz (2020). Elarica began her career in her teens, landing her first role in the Harry Potter franchise.