Screenshots of the location where you find the crests that unlock the Werewolf and Vampire class. This will only work for one of your party members and requires a non story character!
Other Fell Seal: Arbiter’s Mark Guides:
Unlocking the Secret Classes
Look behind the Tree in Ekhinda Falls.
Requirement: Mercenary 4, No story character.
To unlock the Vampire class, you have to push the button on a statue in the Restful Stone cemetary.
This will cause one of the graves to open and you can pick up the Blood Crest.
Requirements: Scoundrel 6, Alchemystic 3, Blood Crest, No story char.
If you did not hire one of the advanced classes, you also need Mercenary 2, Mender 2, Wizard 4 to unlock Scoundrel and Alchemystic.