To make it simple I’ll just go through and explain how Shaman Magic work, how the Shadow powers work, where the powers come from and how Kyven learned them. Everything I list here has come out of the story so far.
Shaman Magic:
Shaman Magic can only be used by someone with the right genetic makeup. If you meet the qualification you must go on a Spirit Walk to learn how to be a Shaman. Now not all Shaman have totem spirits and they get taught by different spirits on their walk. Totem Shaman only get taught by their Totem Spirit and everything they do has to go through that specific spirit. Now a Shaman can learn magic in two ways I know of and with a third possible. One a Shaman or Spirit can teach you the spell. Stalker taught Kyven the lightning spell and the Fox taught him the cold spell. Two they can see a spell done by another shaman and figure out how it works. This Kyven did with the spell he saw Clover use in Deep River. The third and last possible way is if he figures one out on his own, with no example to go by. I don’t believe Kyven has done that yet. Now knowing how to cast the spell is only part of the equation you still need the power to cast it. Now a Shaman can get that power in only two ways. One drain a crystal. Shaman’s can drain crystals and used that stored energy to cast spells. Two ask the Spirits to give the power to them. Kyven being a Totem Shaman has to ask the Shadow Fox for that. Any spell no matter how he learned it the Power behind that spell always come from one of those two places for Kyven to power it: A Crystal or the Shadow Fox. Most of what is in this section is what Stalker taught Kyven at the beginning of his walk, basically Shaman 101.
Shadow Powers:
The explanation of how the Shadow powers work started early in the story, chapter 5 of Spirit Walker. There the Fox tells Kyven about the Shadow Fox Monsters and where the Power for the Shadow powers come from: The Spirit World itself. Unlike Shaman Magic the Shadow Powers use the energy in the Spirit realm no begging required of a spirit to supply the power.
No. They absorb the energy to grant them that power from the spirit world. It is a minor power and does not require so much energy as a crystal holds to enact. It is for them the same as spirit sight is for you, a passive ability.
Now this ability to use the Shadow powers was gifted to the Shadow Fox Monsters by the Shadow Fox Spirit when she made them. This is basically an instinctive power that the Monsters learn how to use on their own.
“You won’t teach me?”
No. The power of shadow is my gift to you. I will not teach you, you must learn on your own, as any shadow fox kit must learn without any help from its mother. You will find, in time, that the gift I have given you can rival your Shaman magic in some ways.
Also you can see here the Shadow Fox tells Kyven that the Shadow powers are her gift to him. Now Kyven as we all know can be a little dense at times and the Shadow Powers is where he is the most dense. Kyven got so caught up in not being human anymore, lusting after Danna and everything else that he didn’t try to do anything with the Shadow powers outside of blending with the shadow. So the Fox being who she is killed two birds with one stone and made Umbra. Bird One more Shadow Fox Arcans, Bird Two someone that Kyven can see use the Shadow Powers.
“You were born knowing what I don’t know. You have instinct, I don’t. She told me that the shadow powers I have could rival my Shaman magic if I learned to use them, but I’ve never tried. Teach me.”
“Teach you? I can’t teach you,” she said. “It’s not something I can really teach. I can only tell you what I can do, but I can’t explain how I do it. I just…do it.”
It was from Umbra that Kyven learned how to make Shadow.
He reached into her little shadowy rabbit, felt the coolness there, and on an impulse, tried to summon that cool feeling through his fur on purpose. He did it the way he called power as a Shaman, he beckoned to the shadow. And it responded! Kyven’s hand wavered, and then vanished within the foggy shadows, becoming invisible within the fog of shadow. Kyven had never made just one part of his body vanish before.
The ability to use the Shadow powers is internal and the power to use that comes from the Spirit world:
It was the innate power of the shadow foxes, what made the monsters, and when he did it, he could feel the power of the spirit world channel through him almost as if he were using Shaman magic
Now everyone likes to point out “hey he doesn’t have his fur anymore and he needs that fur to use the powers. The correct answer is yes and no and the no part is so obvious everyone over looks it. The fur lets him blend in with the shadows due to its coloration and such. Yes Kyven when he first used the Shadow powers, not just blending in, went through his fur to do it, but now I am going to point out something very obvious. Fur is nothing but hair and Humans have hair all over their bodies. It’s not as dense as the hair on an animal but its there none the less. So unless there isn’t a hair on Kyvens body, the only thing he lost is the ability to blend in with shadows, which is not a shadow power. Shadow powers are internal the ability to blend was external dependent on his fur, basically that is nothing but camouflage. It is the same as painting your face and hands black and dressing all black and going outside at night and hiding in the deep shadows. Recap: the only thing Kyven learned from somebody else was how to make Shadow bunnies and create a fog of shadow and he did this by watching Umbra and feeling how she did it. Everything else that he knows he learned on his own the Shadow Fox will not teach him anything about the Shadow Powers, at least not directly.
I know what you are thinking “what about when the Shadow Fox used the Shadow Powers to take Kyven off the Loremaster’s Island?”
Kyven in a way was begging, but not how to use the powers. Basically what happened was Kyven Summoned the Shadow Fox which is a function of being a Shaman and her using the Shadow Powers was how she fulfilled the Bargain struck.
She placed her paws on his shoulders, and the instant she did so, he felt the shadows come alive. They swarmed around him, enveloped him, encompassed him, and he felt a strange cold shiver through his entire body. His spirit sight seemed to fail him, as the light of the life on the bridge above seemed to dim, to darken, to get lost in the shadows surrounding him, and then the shadows receded
Thus have you used up my favor, she told him, though she was very proud. Your offer of sacrifice was your payment for my assistance. You made a good bargain. Now go. Go home, and do what must be done. And know that I am proud of you, my Shaman.
Now the fox didn’t teach him anything, what it was is that Kyven felt the shadows come alive and do what they did. It was basically the same thing he did when he learned the preservation spell from Clover and the Shadow fog from Umbra. They used the powers they had Kyven just figured out how they did that. Right now he still trying to figure out how shadow travel works. Since he saw it done, he knows he can do it once he figures out how and if he can handle enough power.
Ok now this little tidbit I have held back so far because I know if it’s true will not be popular: Clover dies on the mission to stop the gun shipment.
The reason I came to this conclusion.
1. As shown above offering to sacrifice yourself seems something at least some spirits consider a good bargain for their help, even if they don’t take your life.
2. Clover is the one that bargained with the owl spirit and the bargain struck is very interesting for what happened at the end of chapter 4.
Such was the very subtle and effective ways Clover had bargained them protection. The spirit that watched over their shop and them, a wise-looking owl the size of an eagle, was acting in a very subtle manner by removing the desire of the Loreguard to inspect the building or the people who were inside it when the protection was enacted.
Notice the protection was that the desire of the Loreguard to inspect the people, which includes Kyven, was the favor granted by the Owl Spirit.
3. Right after Clover left the Loreguard suddenly got the desire to inspect Kyven. That means the Favor granted by the Owl to Clover was removed. The only thing left is for the Owl to claim his price.
Now did Clover offer her life for that protection and this mission is where the Owl will claim it?
). 
