Solution

Alex made his way to the Lightning Fast Merchant's store. As the sun was setting, the store seed to be on the verge of closing, but when the receptionist saw a young man with the uniform of Dantalian enter, she immediately turned humble and invited the guest in.

"Respected sir, what brings you here from the great academy?" The receptionist quickly asked.

"I'm here on a mission to perform a spot inspection." Alex calmly replied. "Is Mr. Brosh here?" Brosh was the owner of the store and the dubious merchant Alex had come to investigate.

"Inspection?" The receptionist paled immedoately on hearing the word. "The owner has already retired for the day." She managed to squeak out in her panic.

"I would be grateful if you could invite the merchant back to the store. Meanwhile, let me have a look at your accounts." Alex calmly took out a token identifying him as a student of Dantalian as well as a scroll that acted as the inspection permit.

On the rooftop opposite the store, Desiree was quietly observing Alex's every move as she was instructed. She couldn't care less why the headmistress was interested in this young man's actions. For her it was a mission she had to accomplish to the best of her abilities.

As Alex was inspecting the large accounting tomes, a fat man desperately rushed into the store while padding his bald forehead with a kerchief to wipe away his perspiration a of worry.

"Mr. Brosh? You don't have to appear so worried. I'm just here on a routine inspection." Alex smiled a genial smile and took the initiative to shake hands with the tense man.

"I don't understand, young sir, why would my store need inspection?" The owner asked.

"There have been some quality discrepencies in the alchemic materials you are supplying and the rates you are charging. There have been several reports of excessive failures in medicine production as well as accidental poisonings. I came here to verify the cause of this incident." Alex replied while handing the mission scroll to the owner.

He then continued while pointing at the books. "I've discovered several issues with your accounts, especially in terms of discrepent costs and your shop's income. You seem to be receiving a significant portion of profits in unaccountable income?"

"Uh..." The shopkeeper was agitated. "Young sir, you know that we shopkeepers have under the table deals to avoid taxes. However, there's nothing but clean records when it comes to Dantalian!"

"I'm, I did take the liberty to procure some samples of the materials you supply." Alex replied calmly. "Can I have a look at some materials from your store to verify?"

The store owner nodded and Alex calmly walked over to a shelf and picked a herb he had been eyeing for a while. "This seven leaved Pincir is a good quality medicinal material. Quite similar to the stuff I've obtained from the academy. There's just a slight issue here though."

He took out a similar herb from his own bag and then lit it aflame. "This herb delivers a bright blue glowing flame when lit on fire. It lacks any form of smoke and creates an extremely clear and stable flame. But what do we have here? The blue flame is actually tainted by giant tar linings."

"Let's test this herb off your shelf then, shopkeeper." Alex repeated the same process with the herb he picked from the shelf and it gave off the same black-blue flame.

"This-impossible!" The shopkeeper staggered backwards,his face puffed red and he looked like he was about to have a panic attack. "I only serve the best quality herbs. How can it be poisoned? I verify their quality myself!" He howled loudly.

Alex nodded. "I presume this herb's been sitting here for several days? How about we take a look at the produce that you procured most recently?"

"I did today itself!" The fat man bumbled as he looked.towards the receptionist lady. Alex stopped him. "Oh, you don't need to trouble yourselves. Pointing it to me will do."

Alex quickly picked up a similar herb and lit it aflame. The flame was indeed a clear blue and pure. Alex nodded as if he expected it.

"You can see, young sir. I did not poison the herbs. I dare not go against Dantalian!" The man was literally hyperventilating at this point.

"You can stop worrying, Mr. Brosh. I never would doubt your integrity in such matters from the start. Dantalian would never procure a supplier who was so unreliable." Alex calmly spoke as he backed down onto a chair.

"You see, the herbs are indeed doped. But not intentionally. It would be very difficult to poison herbs with such uniformly small doses. This is more like an unintentional effect of the presence of a most suspicious kind of power. Am I right, miss receptionist?" Alex asked suddenly with a smile.

"I..I don't understand." The receptionist stuttered.

"Oh, it's quite simple. A shadow creature who is unable to prevent their shadow essence from leaking, no matter the disguise, would certainly cause a lot of unintentional consequences. Your disguise is most effective, miss receptionist. Perhaps you are a half shadow-being? Yet you made the mistake of working at an alchemist's workshop. Perhaps you thought it was the only hope for you to concoct potions that could continue to hide your aura? There are several herbs missing from the inventory here, exactly those needed to suppress a shadow aura, I might add." Alex explained calmly.

"You... how could you..." The receptionist's frightened facade vanished as a cruel look took over her expression. "So many years of hiding, all my careful amneuvers seen through by a brat? So what if you found me? You have no cultivation of your own and decided to stomp in here to confront me? I will simply kill you and start over!"

The body of the female receptionist began to crack and a gigantic mass of shadow emerged from underneath the skin. The grotesque creature was ethereal, yet physical. It looked like a gigantic demon with twin horns and muscular shoulders towering over the two humans in the store.

The shopkeeper, seeing the sudden transformation of the receptionist into a shadow demon passed out from fear.

Alex shook his head. "Did you think I came unprepared? I expected to meet a shadow race entity before I ever set the first foot out of the academy."

"You were too arrogant" The demon snarled. "You even smell like one of us. Are you a hybrid too, like me? It doesn't matter. You sided with the wrong party. Now die!"

A terrifying ball of shadow suddenly released from the dark shadow that was enveloping the shop and struck directly towards Alex. Desiree was observing the development with raised eyes. She had been told to silently observe the situation, yet now she was in a dilemma. Was she to break cover? Was she to interfere or not? The headmistress never foresaw the boy actually encountering lethal danger. The boy had just said he had prepared counters for the situation.

In her dilemma, she failed to act and then observed with horror as Alex only smiled brightly without doing anything to stop the lethal shadow energy orb hurtling towards him at high speed. The orb collided into Alex's body rattling him like a cannonball into shelves behind and crashing into the wall. He fell down like a rag doll and black blood oozed out of his mouth. His ribs were probably broken.

His vision was extremely blurry, but his smile only became greater, even through the bone crunching pain. He struggled through the black smoke that seemed to be burning his body like an evil furnace and opened his palm, showing a talisman.

"Curse talisman?" The demon asked in confusion. He anticipated that the boy would have had light talismans or weapons imbued with the light or silver element. How else would he be so confident? But a curse talisman? Moreover it was a sacrifice talisman that could only be used on someone willing to accept it. It was a curse method to guarantee an oath. The devil shadow was dumbfounded.

The talisman began to glow like a grey chaotic poison and suddenly, the black smoke from.the shadow ball that had enveloped Alex's body began to burn away. He had used the sacrifice talisman on himself!

At the same time, the demon began to feel a terrible burning feeling in his own body, one that pierced through its very soul and a terrifying cry shattered through the entire city. The demon suddenly found itself enveloped in a silvery flame that consumed it's very soul. Unable to bear it, the demon's mind collapsed and then it's body dissipated as well.

Alex felt his body slightly loosen. "Looks like my guess was right." He smirked to himself as he lost consciousness.