Due to her immense Soul Wavelength, Arachne possesses a Madness Wavelength. This, when combined with her Magic, makes this particular madness particularly powerful. Whenever an individual is caught in her split, spider web-shaped soul, they are ensnared with a spell from her Magic, pulling them into this particular type of Madness.
Those under its influence begin feeling a powerful, painful sensation within their heads, described by Kilik Rung as spiders inside his head that are ripping it apart. Sid Barrett comments that the madness also makes him feel like he's "losing his mind". This madness was powerful enough to affect most of the DWMA and Arachnophobia forces around, including the likes of Sid Barrett, Mira Naigus, Soul Eater, Ox Ford, Black☆Star, Kim Diehl, and Jacqueline O'Lantern Dupré.
However, there are some limitation to this particular madness. Individuals like Harvar D. Éclair, who is described as being 'hardheaded all the time', and those possessing the Anti-Demon Wavelength are immune to this madness. Black☆Star and some of the DWMA forces showed that willpower can resist this madness. In addition, Noah (Greed), most likely due to being an Icon and created from the Book of Eibon, which carries the madness of a Great Old One, felt this madness as some sort of "refreshing breeze".
- ↑ (Yen Press) Soul Eater Manga: Chapter 25 — Stein: The madness inside of me...her madness comes nibbling at the edges of my body...
- ↑ (Yen Press) Soul Eater Manga: Chapter 59 — Soul: Arachne casts her soul out wide in the form of a spiderweb, and any souls that get caught up in her web come under her spell. She pulls them towards the Madness.
- ↑ (Yen Press) Soul Eater Manga: Chapter 58 — Kilik: They're in my head.....spiders...they're ripping apart...the inside of my head!
- ↑ 4.0 4.1 4.2 Soul Eater Manga: Chapter 59
- ↑ Soul Eater Manga: Chapter 58
- ↑ (Yen Press) Soul Eater Manga: Chapter 58 — Kilik: Well, maybe you don't feel it 'cos you're so damn hardheaded all the time, but..
- ↑ (Yen Press) Soul Eater Manga: Chapter 59 — Soul: Maka's Wavelength is somehow cutting through the darkness for me. It must be because I'm in resonance with her. That must be why the Madness has no effect on me.