This specialist Vocation only becomes available for use after completing the appropriate quest; Quest #112 - Ranger Changer.
The Ranger is a rugged, monster sympathizer Vocation. They have the highest Deftness in the game, and have healing capabilities as well. They are a very adventurous class that learns abilities such as Mercy and Wolf Whistle.
The Ranger's Coup de Grace is Brownie Boost, which gives them a temporary increase in Strength, Resilience, and breath attack resistance. The Ranger adds all kinds of opportunities for a party to explore, and they should not be underestimated.