Horn of Geryon
| The horn belonging to Geryon, guardian of the Vestibule of Hell. Legends say this unholy item has the power to call forth the aid of demonic beasts. It is also said, however, that the alliances of these monsters are not certain. Once released, the spirits within this device will dissipate, leaving it inert, though new ones may be attracted as its bearer battles through the dungeon and grows in power and wisdom.
‘So Joshua called together the priests and said, “Take up the Ark of the Lord’s Covenant, and assign seven priests to walk in front of it, each carrying a ram’s horn.’
‘When the people heard the sound of the rams’ horns, they shouted as loud as they could. Suddenly, the walls of Jericho collapsed, and the Israelites charged straight into the town and captured it. They completely destroyed everything in it with their swords—men and women, young and old, cattle, sheep, goats, and donkeys.’
The horn of Geryon is a unique evocable item, found only by slaying Geryon in the Vestibule of Hell. Much like the elemental evokers, evoking the horn of Geryon will surround you with several hell beasts. The higher your Evocations skill, the better your odds of these beasts being allied to you, and the longer they will last for. Once used, the horn will become inert until you've earned enough experience to restore it.
Prior to 0.14, the horn served a very different purpose. Until it was used while standing inside the Vestibule of Hell, the four portals to Gehenna, Cocytus, Dis, and Tartarus were sealed shut. As such, Geryon was essentially the only monster necessary to kill in order to get a perfect 15-rune ascension. Using the horn anywhere else simply summoned a hostile hell beast to attack you (worth no XP).
Prior to 0.9, carrying the horn out of the Dungeon contributed to your final score, granting the bearer 5000 points. Also, before the changes to experience and skills in 0.9, this item was commonly used by high-level characters as a renewable way to "victory dance" Fighting, Dodging, and weapon skills.