i'm a moron.

killed the hydra and golden golem, saved dusk. then i forked over ten dollars for the DLC. is there any other way I can get "cast light" now without fighting the Sanctuary Guardian? Also, should I manage to take that thing out...how far into spooky hard DLC land do I have to venture to pick up the other sorceries and ivory catalyst?

krissy:

it took me an embarrassingly long time to find the merchant too. i saw a little "try rolling" message on the ground and just felt the little lightbulb above my head come up. parrying takes a lot of time to master. you'll have it down to an art form after you've rang the bells and taken your trip through the funhouse.