Yes, according to her ruling, her effect also counts the Extra Deck. Neither player can return monsters to the Extra Deck while this card is face-up on the field.
In fact, this card is the only way to keep Savior Star Dragon on the field.
Thank you for visiting Duel Links wiki by GameA! We update this Yu-Gi-Oh! Duel Links community day by day to provide quality guides and the latest news.