Main Plot :
The world of The Witcher expands in this anime origin story:
Before Geralt, there was his mentor Vesemir a swashbuckling young witcher who escaped a life of poverty to slay monsters for coin.
But when a strange new monster begins terrorizing a politically-fraught kingdom, Vesemir finds himself on a frightening adventure that forces him to confront the demons of his past.
[Source – AnimeKaizoku]