In a way, I think the prestige class works well as an "X"-Slayer, where X is equal to a relevant creature type (or subtype). If it were more broadly applicable, it'd definitely be one of the best martial PrCs (IMO). Maybe almost better as a Ranger PrC thematically.

Otherwise, it's just a Fighter with a better save but weaker in every other way. Energy Resistance and Aura of Courage make it Fighter+, but the class only gets two bonus feats, which makes it more like a Fighter-.