Dewi: The Giant Slayer is a hardback children's book.
Written by Jorie West and illustrated by Dee Levens.

There once was a boy called Dewi (Day-Wee) who lived long ago near the center of Turtle Island, the land we now call America. He was the youngest son of the great Chief Calfseller who followed Creator God in all of his ways. Dewi had six brothers who were all brave warriors and hunters who provided well for their tribe. His brothers loved Dewi and taught him many skills including how to use the bow and arrow that Grandfather made for him.  
But there was an evil warrior across the valley who was threatening Chief Calfseller and all the tribes. He was so big and menacing that everyone around him was terrified. The chief had loved and respected Creator God all of his life and had taught his sons in the same way. Dewi had learned to see Creator in nature but also to hear His voice in his heart.
Dewi obeyed Creator God and became a brave young warrior that stood strong and fearless against the giant warrior.