Avenger : Shrine keepers
The Spirit talker travels from shrine to shrine as they talk to the different spirits of the island. These shrines are kept by a class of warrior known as Avengers. Their every action is guided by the spirits. They whisper in their ear to correct aim, or impart wisdom and power to their strikes. Some say these shrine keepers are all eventually driven quite mad by the voices and powers that flow through them.
Rename powers if you so choose, I’d recommend not, for clarity-sake. Replace Religion from class skill list, with Nature.
Cleric : Sun Worshipers
Offering their allegiance to one and only one spirit, clerics are granted the powers of life and holy fire. These people are often mistaken for monotheists. Though some of them believe that other spirits pail in comparison to their chosen spirit, they still do not debate the resistance of others.
Choose a deity who’s portfolio is similar to what greater spirit you’re looking for. In my example Palor, the sun god, could be used to substitute the sun its self.
Wizard’s spell books : Tattoos
Some sources of magic does not come from working with nature, but through harnessing the power of nature through your own body, and bending it to your will. These arcane casters are tattooed with the eldritch rites that have been passed down from master to student.