The boy has to go in search of the 5 great Adlet who will provide him greater power to aid his fight against the Qalupalik and rescue his brother. But to gain these abilities the boy has to defeat their five brothers to prove himself worthy. The five brothers were exiled and became cannibalistic warriors who are said to serve the Keelut (An evil spirit in the form of a black dog with hair only his feet). If the boy can free the land from their peril only then will the great Adlet grant him the power to defeat Qalupalik and rescue his brother.
I have been thinking of how each character plays and what the benefit of playing them is to the gameplay.
For the boy I was thinking of making him the son of a Shaman therefore giving him the ability to use magic. This would then give the ability to use magic not only in battle but in platforming as well for the player to solve puzzles. For example using the ability of fire could allow the player to melt ice to reveal hidden paths. The boy could also have the ability to climb well for the puzzle platforming sections. Looking into the Shaman I found they use masks for their rituals therefore a way to provide hidden collectibles in the game to level up the characters abilities would be the masks.
Looking into the abilities that the wolf would have - Wolves can sprint fast and jump far distances. Wolves have good sense of smell and hearing. The wolf can howl creating that echoes and creates the illusion of more than one being present. this could be used as a move to stun enemies while the player can attack. Also when the player defeats one of the evil boss brothers each time, the player receives another 'pack' member from the Adlet to aid in battle when called upon.
With the hidden collectables Ravens would be a good character to be hiding the masks from the player so the player has to get them. A normal collectible throughout the game could be fish bones/bones or just fish. These collectibles will just be there for completists to gather.