Yes, it's always specified, however it's been so long that I don't remember which ones does it. A skill may cure venom as well, make sure to check Sarah's just in case.
How do I get to the Fighters' Guild in SankT Leona? Whenever I go up that way Sarah says, "We are not allowed to go in there. It is the headquarters of the Guardians."
No, that's not the fighters guild. Go to where the carriers are waiting for you to take you to Rillia and from there go up. You'll see a big door. That's the guild.
about the venom cure at the guild of Xen Sarah can learn a spell that cures it as far as i know she can learn 1 of 3 spells -healing -damaging -corroding thought u might be interested