HBO's Game of Thrones Prequel Adds Devs' Sonoya Mizuno and More

Sonoya Mizuno will play Mysaria, an ally to Matt Smith’s Prince Daemon.
Sonoya Mizuno will play Mysaria, an ally to Matt Smith’s Prince Daemon.
Photo: Emma McIntyre/Getty Images (Getty Images)

The Thronesverse just expanded, thanks to HBO’s latest casting announcement. House of the Dragon, a Targaryen family-based Game of Thrones prequel, has added four new stars to its already impressive roster.


Joining Paddy Constantine, Olivia Cooke, Emma D’Arcy, and Matt Smith, HBO announced today that Steve Toussaint, Eve Best, Rhys Ifans, and Sonoya Mizuno are in the House (Targaryen).

According to Variety, Toussaint will portray Lord Corlys Velaryon, “The Sea Snake,” a very wealthy nautical adventurer. The Amazing Spider-Man’s Ifans will play Otto Hightower, the Hand of the King to Constantine’s Viserys Targaryen. Best will play Princess Rhaenys Velaryon, Corlys’ wife and the only child of Prince Aemon Targaryen—passed over as heir upon his passing in favour of Aemon’s brother, Baelon, because she was a woman, earning her the title “The Queen Who Never Was”. Finally, Ex Machina and Devs star Mizuno will play Mysaria, a dancer from Lys who eventually becomes the paramour of Smith’s Prince Daemon Targaryen (and eventually, the mistress of whispers to D’Arcy’s Queen Rhaenerya). You know what that calls for.

Sonoya Mizuno and Oscar Isaac serving moves in Ex Machina.
Gif: A24

House of the Dragon was actually the first spinoff George R.R. Martin pitched to HBO. He’ll serve as executive producer and there’s a possibility he might someday even write for it, after he finishes a few other minor tasks. The series takes place during the Targaryen Civil War, about 300 years before Game of Thrones. It will premiere on HBO and HBO Max in 2022.

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Weekend Editor, io9. Push the button, Frank.



I was late on watching Devs so when I went back on Reddit and look at the comments I was surprised to see a lot of hate for Sonoya, a lot of people seem to find her acting cold and monolithic.

I mean, I can understand the criticism but for me her performance was well adapted to the constant sense of eeriness in that series.

If there’s one thing the GoT crew has been consistant with (beside the amazing OST - and Ramin Djawadi is also confirmed to be back!), it’s precisely the casting choice. I don’t really have a doubt they chose her for the right role.