The easiest way for you to get those treasure cards is to go to Dragonspyre, in the Crystal Grove area, and there will be a tower simply called Emberlight's Tower, (it's near the area where the Kyanite Crystalmancers are) where you'll fight a man named Bael Emberlight. According to the wiki, he drops Brimstone Revenant treasure cards.
Unlike some towers in DS, farming this one's relatively easy and quick because there's only one floor so it'll be an in-and-out type thing. Good luck!
The easiest way for you to get those treasure cards is to go to Dragonspyre, in the Crystal Grove area, and there will be a tower simply called Emberlight's Tower, (it's near the area where the Kyanite Crystalmancers are) where you'll fight a man named Bael Emberlight. According to the wiki, he drops Brimstone Revenant treasure cards.
Unlike some towers in DS, farming this one's relatively easy and quick because there's only one floor so it'll be an in-and-out type thing. Good luck!
EDIT: I can definitely confirm that Bael Emberlight does drop Brimstone Revenant treasure cards! I got pretty lucky and was able to get one to drop from him within eight tries. Plus, in order to reach Bael in the first place, you have to do a side quest by speaking with Zarek Pickmaster (if you haven't done so already).