Silver Cove is the second town with light/dark guilds. But they have very limited inventory while in Blackshire you can learn them all (except two highest, which are useless anyway).
What are the two highest? In 7 it was the kinda useless "Heal the caster but age him", which would've been less pointless if it cured everyone and Souldrinker, which was cool but not strong enough for its cost. Is it the same in 6?