I've been looking through the Witch-Hunter prestige class, which is found in a Ravenloft sourcebook. I think it would work well in Birthright as a varition on the Ranger, in fact I think it should be expanded to a full class for both settings, by adding 5 lower levels and 5 higher levels for the complete 20 level range given in the 3e PHB to proper classes.

The reason I suggest this is because the Witch-Hunter has much in common with the Ranger, but is not the same class, in fact it's intended as a Ravenloft-specific prestige class.