Spider Demon (Son)

The **Spider Demon (Son)** (蜘蛛鬼「兄」, *Kumo oni: Ani*?) was a member of the Spider Family.

## Appearance

Son takes the form of a giant spider possessing a human head. His face, like Mother and Daughter, had the same facial features of red dots, white skin and hair similar to his "younger brother" Rui, with the only difference being that his eyes possess dark red scleras, with blue irises and black pupils.

## Personality

Son was shown to be sadistic and cruel, as seen in the flashbacks of Mother's memories when he openly taunted and enjoyed the physical and verbal abuse she was being put through by Rui and Father, while addressing them formally as his parents, showing that he sadistically enjoyed playing the part of being in a "family". Similarly to Father, he was extremely loyal to Rui's cause and played his role as an elder brother in his family without question.

Like most demons, he hated humans; he was responsible for a great number of people transforming into spiders and even ruled over them, making them servants when their mental intellect eventually faded away with their transformation. His taunting and prideful nature was also evident when he continually prodded and mocked Zenitsu Agatsuma over his impending fate as a spider.

Son was also shown to be arrogant and brash, openly insulting his attacker's ability to do just one form and becoming enraged at the thought of dying at the hands of someone he thought so lowly of. In spite of his pride and confidence in himself, he became fearful upon seeing Zenitsu's true power being used and desperately tried to flee back into his house.

## History

Son was presumably found or encountered by Rui in the forests of Mount Natagumo. As with the other members of his "family", he likely once had a more obvious human-like form as a demon, before his transformation upon being given further power and strength by Rui. He was likely one of the oldest members, being part of the family before the most recent member Daughter and relatively young Mother, perhaps indicating that he knows of Rui's true malevolent nature and playing his role to avoid the consequences.

During one occasion, Rui and Father lashed out at Mother over her inability to control her emotions and transforming back into her previous human-like form. Son saw the confrontation and only laughed at the abuse she was suffering, remarking that "Mom's in trouble with Dad again!".

Son lived in a clearing amidst the forests near the middle of Mount Natagumo, residing in a suspended wooden house that is supported by long webs strewn in the tree tops. Also hanging from the webs were his most recent victims, eventually becoming subservient to him.

## Synopsis

### Mount Natagumo Arc

As Zenitsu Agatsuma panics at the sight of Demon Slayers in the process of becoming spiders, Son descends from his house, causing the terrified Demon Slayer to flee. Son warns him that he had already lost, telling him to look at his hand. He notes that the Demon Slayer had been bitten by a spider and poisoned, and would become a spider himself in half an hour's time. Taking out a watch, he explains the various effects the poison would have to his opponent, as well as the times they would take place at. Zenitsu freaks out at this knowledge, running and climbing up a tree, prompting Son to chide and question his decisions. He went on to tell the youth that he has nothing to fear, for he would lose his intellect upon transformation, only to be irritated by his terrified, brutally honest comments.

As Zenitsu continues to complain, Son became bemused and similarly confused as the youth fainted and fell out of the tree. However, the Demon Slayer quickly recovers, charging at him, who spewed acid-like venom at his aggressor. Zenitsu dodges the attack mid-air, then lands on the ground, while the Spider Demon contemplates this new change in circumstance. He orders his spider minions to attack Zenitsu as the youth prepares another attack, which was dodged, prompting Son to spew venom at the Demon Slayer again. Although this too was dodged, Son was able to confirm that Zenitsu could only use one technique, prompting him to gloat at his apparent victory.

   The Spider Demon continues his assault with yet another spewing of venom, this time managing to strike Zenitsu, while his minions attacked the weakening youth. He orders them to envenomate the Demon Slayer, which was dodged, but he noted that the overexertion was causing his opponent to vomit blood, which prompted him to label Zenitsu as useless to him. However, the youth prepared to resume his attack, while a surprised Son noted the air was shaking. He retreats back into his house, letting loose another spray of venom, but Zenitsu's enhanced **Thunderclap and Flash, Sixfold** was able to reach him instantly, allowing him to sever the demon's neck. Son's last moments were of utter disbelief that Zenitsu had defeated him, his body hitting the ground in two parts before fading into ash.

## Abilities

**Spider Physiology:** Out of every member of his "family", Son possesses the most spider-like traits, harboring the eight legs, an abdomen and a thorax of a spider. And like a spider, he is able to form long strands of silk, shown to be strong enough to support a small house above a forest clearing and hold numerous victims suspended mid-air.

## Fighting Style

### Blood Demon Art

**Poison Manipulation:** Son's most potent and dangerous ability is his power to generate and manipulate deadly poison.

* **Spider Conversion -** Son reveals that one of his venom's possesses the ability to convert a human being into a spider like creature, with the only human trait remaining in them being their human heads, turning them into the same spider-human hybrid like himself, completely losing all intelligence and becoming subservient to him. The process of the transformation itself requires at least 30 minutes for the victim to be completely transformed. Once the poison is administered, the victim will begin to feel tingling and pain in their limbs. Secondly, they will start feeling dizzy and nauseous. Finally, their bodies will shrink and they will black out, When awaken they are transformed into a spider hybrid. However, Shinobu Kocho was able to restore his transformed victims back into their human forms through her extensive medical knowledge and monthly doses of an antidote.

### Techniques

* Description
* Demonstrations

* **Poison Sputum** (斑毒痰, *Fudoku tan*?) - A spitting venom attack, that is capable of dissolving what it touches.

## Battles

Spider Demon (Son) Battles

**Mount Natagumo Arc**

* Zenitsu Agatsuma vs Spider Demon (Son)