UNNAMED MEMORY SEASON 2

The second season of Unnamed Memory. Seeking to end a curse thwarting his lineage, Prince Oscar sets out on a quest that leads him to a powerful and beautiful witch, Tinasha, and he demands a unique bargain: marriage. Though unenthused by the proposal, she agrees to stay in his castle for a year while researching the spell cast upon him. But beneath her beauty lies a lifetime of dark secrets that soon come to light. (Source: Crunchyroll) — Description from AniList community (anilist.co).