User blog comment:Sylvandyr/The math behind the Battle Arena/@comment-26464603-20150604135754/@comment-5089372-20150604145457

Yes, I can confirm the Sorceress Dragon (along with the Dark Crystal Dragon) are classified as unbreedable.

This table hasn't been updated in a long time so maybe I will start gathering the missing dragon info and add it (might take a while though).