"Umm... The more energy, the more heat they take and their color seems to be a clear indication of what was previously said."

Speaking in a completely confident manner, as if he were stating a fact, which perhaps he is, Christopher looks at the light show in front of him. 

There were four dry branches, which are stuck into the ground and on them are perched flames of different colors. Each flame has its unique kind of beauty, be it the aggressive orange, the static white or the comforting yellow. 

Knowing that this supernatural phenomenon is out of his scope, Christopher looks to the side, a place where Saya can be seen floating. 

"I've never seen anything like this before. Normally fox demons use fox flames for their defense and attack."

"Fox flame? What an unoriginal name. If I may say so."

Stroking his long beard that reaches his chest, Saya begins to walk a few laps around the four flaming branches, then after a few seconds gives Christopher an explanation.

"Yes, it seems to me that it used to have another name... Something like... Magic fire. But then it kept changing or was it that the technique opened up into two different paths at some point, well I don't remember, but me."

"Saya, please just get to the point!"

Shouting with clear annoyance in his voice, Christopher looks with tired eyes at Saya, though Saya doesn't care and points towards the flames. 

Within moments the flames had changed in size and power, causing the branches they rested on to become charred. 

"Oh, it seems that in addition to the amount of energy you inject into them, your emotions also have an effect on their qualities. See now they can even destroy, which they couldn't before or maybe it was simply because you didn't want to destroy anything... Okay, okay, I'll explain."

Finishing a cursory analysis of Christopher's ability, Saya lets a branch go through her body, before giving him a "I already told you I'm immaterial in this form" look. 

"The most marked difference between the two lies in their utility. While the fox flame is primarily a spiritual attack, the magic flame is more destructive to the environment and the enemy."

"I see, I see... Well, I don't really see anything, it's literally nighttime and the only source of light is these things. On the other hand, I guess it aligns more with the characteristics of magic flame, though... I'll be right back."

Lifting his body from the seated position he's been in all this time, Christopher lets out some bad jokes, then takes off into the dark forest and disappears into it in a few moments. 

"Which way did he go and what is this?"

Appearing from another direction with silent steps, Kikyo who has her black hair clearly wet and wears the classic priestess outfit, approaches the area illuminated by the flames, before looking towards Saya in search of an answer. 

"Those flames are from the ability of, of, because it must have such a strange name... whatever. Can you tell if they are influenced by the pearl fragments?"

Taking a serious face and looking towards Kikyo as if searching for any ups and downs in her face, Saya looks disappointed to notice that no emotion is reflected there, though he shrugs it off as he is used to it by now.

"No, when it comes to using shards to enhance spiritual abilities, only these cases can happen. Create a new ability, awaken a latent ability and enhance an existing ability. I would never twist the root of the ability itself, all these flames share the same output, only some go further thanks to more energy in them."

"So they are all the same, only their heat and color differ thanks to the large amount of energy put into them. Like the difference in heat between a small campfire and a thick burning forest, it all comes down to the amount of material burned."

Nodding to himself as if he had arrived at a satisfactory answer, Saya and Kikyo's attention is drawn to the forest, from where a few explosions are heard before a shrill scream rings throughout the place, and in a moment Christopher emerges from there with a strange yokai under his arm. 

"Welcome. Saya, can you pass me one of those?"

Giving a glance to Kikyo who stares at him, no more exactly she is looking at the youkai now under her foot. 

Christopher gives her a quick wave, before speaking to Saya, who snaps out of her stupor and throws one of the branches at him with clear doubt on her face. 

"What are you doing?"

"That would be asked before you give me the branch with the fire, but I will answer you, for it is strange to see you with that puzzled face."

"Demons and your pride."

"Um."

Overlooking Saya's words and Kikyo's slight confirmation, she grabs the branch still burning in flames and holds it in front of her face. 

"Their nature is not magical flames, as you can observe if I don't get angry, they don't burn anything. That destruction and power, seems to be a plus."

"Do you think they are fox flames?"

"Oh, no, no. If they were those, their power of destruction would be little and they would only work mainly against yokais."

Shaking his index finger, Christopher seems to have noticed that he has already raised expectations to the sky, so he lets his thoughts out. 

"I think it's neither, but rather a fusion of both. Before you speak, let my friend here help me check it out."

Stomping hard on the youkai writhing under his foot, Christopher brings the orange-red flaming branch closer to him, though he lets out a few screams the flames do him no harm whatsoever. 

"Okay, these don't work. Next one."

"Stop, take a closer look."

Approaching the yokai writhing on the ground, Kikyo knelt down and ignoring its roars, traces a small wound in the flesh with her fingers. 

"It was effective, only that the purification was so mild that it didn't affect the soul."

"Slight and quick explanation... Please."

Losing all that pride that previously came out of his person, Christopher looks with hopeful eyes at Kikyo. 

She seemed to see it coming, perhaps she had already accepted that Christopher was uneducated in these matters, but she still doesn't show it on her face. 

"Negative(Yokai) and positive(Human) energies are self-exclusive of each other. It is not the arrow with positive energy that purifies them, but it is the reaction generated by these two."

"So the arrow makes an opening in the flesh, while the positive energy enters from there into the soul."

Using the first analogy that comes to his mind, Christopher shows a realized face, as if he had discovered a great mystery today."

"The bad thing about that method is that the human must have more spiritual power than the yokai, because if he is less powerful, the positive energy will be overwhelmed and the yokai will not be purified."

"There goes my admiration for monks and priestesses... What? I'm sure you are special even among the special ones Kikyo."

"He's right, I've never seen a person with so much spiritual power."

Christopher was very clear about the danger Kikyo represents, his instincts are quite accurate in that regard. Saya meanwhile, he is a spiritual being and elder, he can easily determine Kikyo's power. 

"Good, We've been briefed and now it's time to get on with the tests."

"You know it works, you're not going to stop."

"Of course not Saya. Now I know it works, so I must learn how much energy it takes to purify one of them."

Being satisfied with the reason given, Christopher now takes the branch with the orange flame and designs to continue with the tests. 

"But if you barely manage to control your power."

"That hurts, but I accept it... That's why I'm going to use twice the amount of power needed, all so that they are absolutely purified."

"As you wish."

With no more desire to go against the flow, Saya simply stops preventing Christopher from continuing his tests.