Rainbow Poison Book

The Rainbow Poison Book, also translated as the Seven-Colored or Seven Coloured Poison Book, is the ancient rainbow scroll Little Fairy Doctor discovers in the Qingshan Town cave. Its recipes help turn her early medical knowledge into a practical poison craft, later supply a method for sealing Xiao Yan's Demon Poison Spot, and remain useful enough for Xiao Yan to borrow while researching Qing Lin's poison. (Chapters 117, 146–161, 811, 1272)

History

Discovery and division of the cave trove

Little Fairy Doctor opens a stone box in the hidden cave and identifies the rainbow scroll as a manual recording ways to make poison. Xiao Yan briefly examines it, but agrees that she should keep it: his own training and alchemy already demand his attention, while her elemental affinity prevents her from following the alchemist path she originally desired. The transfer is an agreed division of their discovery, not an item Xiao Yan owns and later gives away. (Chapter 117)

The manual soon becomes central to her ability to survive pressure from the Thousand Medicinal House and Wolf Head Mercenary Company. She studies its recipes where medicinal ingredients are available, prepares room defenses and antidotes, and uses a formulation capable of disabling numerous weaker mercenaries. Her effectiveness still depends on obtaining ingredients, testing compounds, and applying them without exposing allies; the book supplies knowledge, not automatic poison effects. (Chapters 146–150)

Recipes, risks, and the Woeful Poison Body

During the pair's training in the isolated valley, Little Fairy Doctor continues consulting the scroll and makes poisons such as Falling Soul Powder. That powder irritates and temporarily seals vision, can affect its user as well as a target, and therefore requires an antidote and careful deployment. Other recipes support pills for resisting weaker snake poison. These examples show the manual's breadth across attack, escape, and countermeasure rather than a single named supernatural ability. (Chapters 155–156, 161)

The book also contains information about the Woeful Poison Body. Xiao Yan uses it to understand that Little Fairy Doctor's consumption of poison is tied to her constitution, while the later story shows that information alone does not cure or fully control that body. The manual helps interpret and manage poison; it should not be credited with creating her constitution or with every innate effect the constitution produces. (Chapters 155–156)

Later medical consultation

Little Fairy Doctor later applies a poison-sealing method learned from the book to delay the Demon Poison Spot in Xiao Yan's chest. The seal works in combination with his Heavenly Flame and is expected to suppress the outbreak for roughly two years, not remove the danger permanently. This is a treatment use derived from the manual and demonstrates that its value extends beyond manufacturing toxins. (Chapter 811)

In the Falling Star Pavilion, Xiao Yan borrows the book while searching for a way to remove Qing Lin's Emperor Python Heart Eroding Poison. He studies it alongside Yao Lao's medical texts for several days before developing a treatment. The loan does not transfer the book's ownership, and the cure is the result of comparative research and Xiao Yan's preparation rather than a ready-made antidote simply copied from one page. (Chapter 1272)

Abilities and properties

• The scroll records poison recipes and preparation methods. Demonstrated results include slow-acting room poison, disabling powder, Falling Soul Powder, antidotes, and protection against some weaker snake poisons. Their effects require ingredients and correct preparation by a practitioner. (Chapters 146–150, 155–156, 161)
• It includes poison-management knowledge as well as offensive formulas. Little Fairy Doctor derives a temporary sealing method for the Demon Poison Spot, and Xiao Yan consults the book during research into Qing Lin's poisoning. (Chapters 811, 1272)
• Falling Soul Powder does not distinguish friend from foe and can temporarily blind its user without an antidote. This documented hazard illustrates why possession of the manual is not immunity to its recipes. (Chapter 161)
• The manual discusses the Woeful Poison Body, but it neither grants that constitution nor provides a demonstrated complete cure. Little Fairy Doctor's innate poison accumulation and later power should remain distinct from the book's learned craft. (Chapters 155–156)
• The supplied evidence does not establish a formal technique rank, named author, or exhaustive table of contents; those details are therefore left unspecified.

Ownership and custody