The following items can be found at citadels throughout the Five Isles.
50 gp (extra page 10 gp)
A Book of Names contains pages of information on identifying the influence and characteristics of demons. To look up a demon in the Book of Names, a character must make an Investigation Check with a DC equal to 8 + the Demon's CR. On a success, the Book of Names contains information about that demon. The character gains advantage when making Intelligence checks to find information about the demon. The character also knows the True Name of the demon.
A Book of Names contains information about three demons. Extra pages can be purchased for 10 gp each, allowing more demons to be identified.
25 gp (3 uses, 5 gp to refill each use)
A small cask of thick wood, containing blessed water. Holy Water burns the flesh of aberrations, fiends, and undead, dealing 1d4 radiant damage upon contact. If a jar is filled with Holy Water, it can be used as a ranged weapon, dealing 2d4 radiant damage to such creatures.
The Holy Water can also be used to draw a magic circle (1 use for a medium circle, 2 for large or huge).
Censer 100 gp, Incense 10 gp per use
Incense burned in a blessed censer can confuse a demon's mind. As an action, a character may light the incense, creating a 5 ft. square of smoke adjacent to the censer. For the next 1d6 rounds, the cloud of smoke expands by 5 ft per round. A strong wind disbands the smoke.
Any aberration, fiend, or undead caught in the smoke suffers disadvantage on Charisma, Intelligence, and Wisdom saving throws.
10 gp (2 uses)
This charcoal has been collected from churches or holy relics burned by heretics. It still possesses the power of the faithful who worshiped its original form.
Consecrated charcoal can be used to draw a magic circle (1 use for a medium circle, 2 for large or huge) or brand a demon. Each piece of consecrated charcoal can be used twice before dissolving into dust.
300 gp
These documents are almost impossible to find, and are a controversial item in the Church of Tael. They contain the mad writings of heretics whose beliefs broke the laws of the Church. However, reading these rants and raves can help a Hound find language to trick the suspicious minds of demons.
When a character attempts to Answer Falsehood With Falsehood, they gain an advantage on Charisma (Deception) checks if they read from the Documents of Heresy.
25 gp
The ringing of Iron Bells strikes fear into a demon's heart. When holding and ringing the iron bells, a character gains advantage to Charisma (Intimidate) checks when attempting to Convoke the Wrath of the Righteous. However, the Iron Bells will drive many demons into a maddened rage; demons have advantage to melee attacks against anyone ringing the Bells.
10 gp
A pure iron brand may be used to brand a demon. The brand must be heated for a full round in a fire before the character attempts a melee weapon attack. If the character misses, the brand cools and must be heated again.
75 gp
A character may apply Iron Manacles as an action when grappling to restrain a demon. The Iron Manacles are painful to the touch for a demon. The demon may attempt to break free with a Dexterity or Strength check of DC 20, but suffers disadvantage to these checks. The Iron Manacles have 30 hit points, and have resistance to melee attack damage from aberrations, fiends, and undead.
15 gp (3 uses, 2 gp per use)
This glass or clay jar has been filled with soil taken from sites of holy visions and miracles. The Hallowed Earth can be used to create a magic circle (1 use for a medium circle, 2 for large or huge). If the soil is spilled onto the ground (1 use per 5 ft square), anyone standing on it has advantage against magic cast by aberrations, fiends, or undead.
25 gp
This knotted leather whip has been inscribed with holy scripture. If a mortal who was once faithful to a demon lashes themselves with the whip while calling for their master, they gain advantage on their Charisma (Deception) check to fool the demon.
5 gp for cloth, 20 gp for fragrant oils (10 uses)
If this cloth has been ordained with fragrant oils within the last day, it grants advantage to saving throws versus airborne poison and disease when held to a character's nose and mouth.
80 gp for mask, 10 gp for each use of fragrant herbs
This long, conical mask, often shaped like a bird's beak, can be filled with fragrant herbs to protect its wearer from diseases. While wearing the mask, a character gains advantage on saving throws versus airborne diseases and poisons. Each use of fragrant herbs lasts for one week.
1,000 gp
When saints die, parts of their bodies are kept by cathedrals as items of power. A character carrying a reliquary, such as a mummified finger, a vial of blood, or a knot of hair from a saint, gains advantage to Charisma (Persuasion) checks when performing the ritual Declare the Divinity of the Word. Furthermore, if the character binds a demon to the reliquary, the reliquary becomes a powerful magic item.
400 gp
When roseash is mixed with tattoo ink and applied to a character's face, it grants the character advantage on saving throws versus airborne diseases and poisons.
20 gp for 20 ft. of Rag Rope, or 2,000 gp for 10 ft. of Saint's Hair Rope
Saint's Ropes are woven from the clothes or hair of saints. A Saint's Rope can be used to create a magic circle (a large or medium circle with rag rope, or a medium circle with saint's hair rope). A character in a grapple with a demon can use their action to restrain the demon with Saint's Rope. Rag Rope has 10 hp and can be burst with a DC 22 Strength check. Saint's Hair Rope cannot be broken, but a demon can escape with a DC 30 Dexterity check.
50 gp, 10 uses
The blessed ink from this jar can be applied to the palms of a character's hand. When applied, the ink allows the character to restrain a demon with their bare hands, by successfully entering a grapple with the demon. Furthermore, unarmed attacks against an aberration, fiend, or undead deal a bonus 1d4 radiant damage. The ink lasts for 10 minutes.
Alternately, a character may pay 300 gp to have their hands tattooed with holy symbols using blessed ink. Once this is done, the character may always restrain a demon with their bare hands.