Solution.

Gaius reclined in the sofa to think how to better explain what a Nephilim was. While he was thinking Yukiko brought some tea and served them all.

“””””Thank you.”””””

Gaius sipped some tea before starting.

“Do you already know what a Nephilim is?”

“Son of a human and fallen angel. He is strong both physically and magically and tends towards evil. Cannibal.”

“Technically they're not cannibals since they aren't human to start with. Those are the basics indeed, but they are all I know about their specific nature. I don't have much more to say. Nephilim are rare and their abilities aren't unified, they depend on their progenitors. But I have a test that can determine it. Give me your hand.”

Terumi brought his hash forward. Gaius grabbed it and flowed his Touki through it. He rubbed his nose while humming before he summoned Reiko and made him bring Gaius some tools. Once he had them he prickled Terumi’s hand with a pin and collected the blood that flowed in a flask.

“I will dissolve your blood in a water-dichromate-spirit residue dissolution. I will then stimulate it both with Touki, magic and both at the same time and observe the result. Through the colour taken and the effects observed we can guess what kind of abilities you will develop. Then I will introduce various materials to see if they cause any reaction. Finally we will move to elements.”

He proceeded with the tests, Touki and magic alone did nothing but together they showed a reaction. The dissolution turned turbid and of a greenish blue colour. Small arcs of electricity danced through the liquid and a small cloud appeared above the flask. He then introduced a silver coin in the mixture but both the liquid and coin remained unchanged. He did the same test with gold, iron, steel, aluminium, and many more metals. None of them showed any reaction. The next materials were organic. Flesh, plants and fungi were slightly scorched. Gaius made Terumi introduce the cut in the flask and it regenerated slightly. He tried many other inorganic materials but none showed a reaction.

“Your powers are related to storms. Lightning, water and wind will appear in your repertoire. Maybe even climate manipulating if you grow strong enough. To activate them you will require both magical energy and Touki. Good news is you have no material weakness, bad news is you have no amplifying materials. At least no easily available ones, you may have affinity for rarer ones. You also show increased resistance towards poison and illnesses.”

He continued the tests, this time placing the flask on a magic circle he hadalready prepared on a skin.

“This is a basic portal circle. I will connect it to several dimensions and places and see if special circumstances affect your abilities.”

The circle shined in various colours but mostly didn't show reaction. However four times the flask flared and once it dimmed until it turned transparent. Gaius nodded once he tried everything he knew of, and put his tools away.

“Diagnosis complete. In conclusion I can say. Proximity or contact with lightning, water, or both will increase your power. Ingestion of oranges will also power you up, bizarre. Why oranges? Leaving weirdness behind proximity or contact to holy or blessed things also power you up while cursed or demonic properties are ignored completely. I will test the latter further. Your weakness is hospitality. Beyond the usual problems with breaking hospitality you can't be invited somewhere in good faith and act against your host if you accept. Judging by the extreme reaction you will faint on the spot if you try.”

Terumi was actually happy with the last restriction, since it kept him from harming people and didn't seem to hamper him too much. Akihiko saw his relief and explained to him the actual gravity of the weakness.

“Don't be so happy. If you are fooled into accepting hospitality, as long as they dont break it first, you will be unable to act even if they are torturing children. It is not a common situation, but you will be helpless if it happens.”

Terumi gulped and nodded.

“Got it.”

Gaius had started the last test. From a sealed box he retrieved a lock of hair and submerged the tips on the liquid. They burned. Gaius frowned at this. He then tried to curse the flask but it didn't do anything.

“Ryuunosuke. Your sword.”

Ryuunosuke passed his tsurugi to Gaius. Gaius took some of the dissolution with a Pasteur pipette and dripped it on the blade.

“Pyram, Glacies, any reaction?”

Childish voices sounded in his mind.

“Some of the corruption has been purified into pure spirit, father.” Commented Glacies.

“But we aren't harmed at all! Don't worry dad.”

“Alright Pyram. Miss Date, do you have anything that belonged to Terumi’s father?”

“I have some of his blood.”

Everyone stared at Yukiko.

“What.”

“What kind of relationship did you have?”

“I took him in when he was injured and nursed him to health. I still have the bandages and clothes he used since he forbid me to throw them. Now that I know about magic I think he was worried about someone getting in.”

Akihiko shaked his head and denied that hypothesis.

“Probably not, a fallen angel doesn't fear humans. He probably feared someone detecting the blood and being discovered.”

“Will you get them please?”

The mother nodded and went to get the rests while she was gone Kotone bothered Gaius to tell her what he had thought of, but he didn't want to speculate.

Once he had the bandages in hand Gaius repeated the process that he did on the sword. The bandages were singed and smoked a little.

“Intriguing.”

“What is intriguing?”

“Well. Terumi has major anti evil and purification properties. He harms demons and fallen angels and purifies corruption. He doesn't actually harm those that aren't evil but have corruption. He is incredibly well suited for dealing with possessions. And evil beings in general, particularly those of abrahamic origin. He is also immune to simple curses, but big ones affect him albeit at a lowered rate. This is really at odds with his nature. Does that answer you, Kotone?”

“See Terumi, you are so good that even your blood tolerates no evil.” Commented Akihiko.

Gaius’ eyes widened as he had a crazy idea.

“That's it! Great idea Akihiko!”

“What?”

“Terumi! I need to corrupt you a little and draw blood again.”

“But won't I-”

“Temporary! Don't be a baby let me corrupt you.”

Kotone snickered at the phrasing but everyone ignored her dirty mind. Gaius put his hand on Terumi’s head and flowed corruption. The change was obvious and swift. Terumi’s skin turned grey and his lengthened. He was about to try an bit Gaius when he finished drawing blood and purged him, making him return to normal.

“I feel sick.”

“Yep. Corruption is no fun.”

“How do you two deal with that all the time?”

“Well…”

Gaius ignored the conversation and repeated the tests. This time the results were different.

“I was right!” He shouted. “When you are good your characteristics are the former but if you are evil they change. You gain a weakness to silver and holy and blessed things. In exchange you are empowered by evil, demonic things and curses. You also naturally produce corruption.”

“So my powers change depending on my alignment?”

“Yes. If this is how all Nephilim work it is a very interesting race indeed. As if you oscillated between holy and demonic. Interesting.”

He began smiling at the possibilities and entered his own world.

“That's good kid. Now you have something to indicate you when you are deviating from the good path.”

“That is awesome. You are awesome.”

“Thanks Ryuunosuke.”

“But still, I am surprised that you know how to identify powers Master. Aren't you a noob?”

“Hm? Oh yeah. But my main disciplines are summoning and dimension magic. Both of those require knowledge of how creatures work and how to identify traits, otherwise you may end up with dead summons or dying when you cross to an uninhabitable dimension or planet.”

“Can you identify me?”

“No need. Kitsune are well documented. No weaknesses or strengths and judging from your fight yesterday you have inherited foxfire and illusions. Both are Senjutsu-Touki techniques. Foxfire is spiritual in nature, it only harms those the user wishes to harm and deals damage to the spirit. This causes difficulty in controlling magic and ki or Touki, as well as exhaustion and depleting ki.

Illusions should be obvious. This kind is mental and spiritual. You can fool the senses of others to make them see what isn't there. If they believe these illusions they can actually cause damage to the spirit, to the same effect as foxfire but less reliable, and make the mind to shut down from stress. Making others faint basically.”

“Cool.”

The conversation died while Terumi's no Kotone thought of their abilities. Meanwhile the others talked about different kinds of summons and Gaius’ advances in his grimoire.

“It is going mostly well. I have written about a hundredth of the rituals. It should only take me a bit over eight years to complete it.”

At that point Terumi interrupted.

“About, umm, the elephant in the room?”

“You mean how to avoid turning evil? I leave this to Gaius, this is his specialty.”

“It is?” Asked Kotone.

“You didn't know why he became a hermit monk?”

“He was a monk?! Master, tell us all the gossip!”

“Not much to say. I was extremely bloodthirsty so I retired from the world to achieve spiritual growth. It worked to the poi i got Senjutsu. Once I was finished, by reaching my objective, I came down from the mountains. More or less, I have spkipped some details.”

Kotone nodded happily, but when he didn't continued she cried in outrage.

“That's all?! You know my secrets and you don't tell me yours?”

“I know as much of your secrets as you do mine. The overview but not the specifics.”

Kotone grumbled but she relented.

“Then can you help my son?” Asked Yukiko hopefully.

“No.” Gaius crushed her hope without mercy. “We are too different. My methods wouldn't work, and I doubt he either wants or can be a hermit. I can only give him advice…”

Gaius froze at that moment, feeling a strange pressure in his chest. He looked at an envelope in the desk that he hadn't noticed until then. There was an aura of holiness coming from it.

“What is that?”

“The angel gave it to me. Said the Vatican kept it for people like me, that wished to be good but had evil thoughts. For Nephilim and reforming criminals.”

“Probably some saint’s relic. Can I open it?”

“Sure.”

Gaius took the envelope and took out a wooden crucifix necklace from it.

“What the hell.”

“What is it?” Asked Akihiko. “Is there something wrong with the crucifix?”

“Yes. It is my old crucifix from my hermit days. It should have been lost ages ago. How? And why?”

Gaius felt overwhelmed. Why did this still exist? Why was it used to banish evil thoughts? Was he actually so faithful that one of his possessions could become a holy object. The questions run through his head, both hopeful and disbelieving.

His struggle ended when Ryuunosuke noticed a letter on the envelope and read it out loud.

“Good day, Mister Date Terumi.

We of the Treasury are glad to present you with the Hermit’s Crucifix also known as the Enabler of Redemption, the Penitent’s Aid, the Ender of Crime. This holy relic was created when one of the forefathers of our Church, the hermit monk Gaius Atiius Quadratus, managed to overcome his evil nature and reach the spiritual strength to never give in to them. Since then it has allowed countless people to leave evil behind and rise anew as righteous men and women.

While the necklace can't banish evil outright it can suppress it, to make evil impulses less effective. At the same time it will reinforce your spirit if you manage to surpass your vile base nature while burning hot when you give in to them. The pain will allow you to turn back from that boundary by making you acknowledge it.

This is what happens normally. But we have heard, and are proud, that the honoured Gaius is your master. We believe that in his presence the effects of the necklace will improve. It should still do what it does but better. We hope it is effective in allowing you to remain in the path of good.

Sincerely, Bishop Ramón Martínez.

PS: We would greatly appreciate if you convinced Gaius Atiius Quadratus to visits us. It is not everyday that we can meet one of the men capable of infusing objects with their faith and good to make holy artefacts. We'd be honoured to have him.

PSS: You may note a decrease of sexual drive. That is one of the effects that don't matter to you but that monks have found useful.

And it ends. Wow Gaius they truly respect you.” Ryuunosuke chuckled before turning to Gaius. “Gaius?”

Gaius was crying, but they weren't tears of sadness but of joy.

“I had always doubted. Am I good? Am I a good christian? I guess I have my answer now. I gave birth a holy artefact. I… It feels good to have your faith rewarded like this, honestly.”

He kept basking in the joy of having his beliefs acknowledged by God himself, for only Him could have allowed for a mere symbol to gain such power. In reality it was a bit more complex than that. Just his awakening to Senjutsu had given it minor properties that he had never noticed, reflecting his struggle. But its transformation into a holy relic had truly been the work of higher powers.

They all waited for him to regain his composure. All of them knew how great it was to have doubted yourself, your quality of character, but have something show you were right, you weren't worthless or evil. They all knew how liberating it was. So they understood and waited.

“I am fine now. I guess this solves the problem. Put it on Terumi.”

Terumi took it from Gaius and did as he was told to. When it touched his skin he could feel the difference. When earlier he looked at Kotone and felt like he had to take such a beautiful woman for himself he was now just slightly aroused, and after a second just appreciated her beauty. Where he felt like he had to rise over Gaius and dominate him he now only felt the usual, the need to prove himself to him. The many thoughts that drove him to evil, even those he didn't realised he had, had died down. His mind was much clearer. And he felt oddly calm in the presence of a beautiful girl.

“This really works. I feel nearly normal, a bit aggressive but normal.”

“Problem solved then. Sorry to interrupt this but I have an appointment with Ken to negotiate the appraisal of the objects recovered from the auction.” Akihiko had the decency to look sheepish while saying this.

“Right, right. Sorry to take your time everyone.” Apologised Terumi.

“Don't, it was time well spent.” Reassured him Gaius with a smile.

Terumi smiled back at him.

“Actually I have a question. How can you be. A forefather of the Church? And what do you mean the necklace should have been lost ages ago?” Kotone wasn't about to let this question go unanswered.

Gaius closed his eyes before he came to a decision.

“I will tell you next class. Kishi should also be there.”

“What about-”

“We already know.” Interrupted Ryuunosuke.

“What?!”

“Goodbye miss Date, Terumi.”

“Bye.”

“Good evening.”

“Don't ignore me!”

“Thank you for helping my son.” Yukiko bowed.

“See you tomorrow, Master, Kotone.”

Gaius, Akihiko, and Ryuunosuke began leaving. Kotone had no choice but to run after them and kept complaining about their keeping of juicy secrets while in the car.