Cryptoglyph

The Cryptoglyph is a Hive artifact, imbued with incredibly powerful magic. It was used by Hashladûn, Daughter of Crota and her sisters to command and protect themselves against the Nightmares generated by the Pyramid beneath the Scarlet Keep. The Guardians learned of the Cryptoglyph's existence following Hashladûn's fall at the top of the Scarlet Keep. With this information, Eris Morn speculates that the Cryptoglyph would be located in the most forbidden location of the Hellmouth, the Catacombs. Despite the immense danger and total darkness, Eris asks the Guardians to descend into the Hellmouth again to acquire the Cryptoglyph, knowing it is essential to combat the Pyramid's wicked energies. Traversing deep into the Hellmouth, the Guardians reach the resting place of the Cryptoglyph but after taking it, the relics caretaker, Besurith, Daughter of Crota (Hashladûn's sister), emerges to stop the theft. Despite her sorcery, the Guardians defeat Besurith, allowing them to race back to Eris with the relic in hand.

With the Cryptoglyph, Eris uses it to empower her Lectern of Enchantment in order to forge more armor needed to infiltrate the Pyramid and resist the Nightmares.

Trivia

 * When first found in the mission, the Cryptoglyph appears almost exactly like Eris's Lectern of Enchantment.