Moon Staff of Lileath

 is an arcane item added in Total War: Warhammer II. It is a legendary item for Teclis.

As of the Potion of Speed Update, it is no longer a hidden item, the quest for it unlocks for Teclis after a certain level.

Quest
Moon staff of Lileath: The vermin of Hruddithi

"We search for the Star crown. But that was just one of three sacred giftsbestowed upon us by the godess Lileath. The moon staff was another, wich is why you must keep it close, High loremaster, for it is precius as it is powerful. Yet its power currently wanes, for the Winds of Magic unravel. Nerby deposits of Warpstone further tamper with the staffs potency. Purge the area of vermin and the staff may awaken."

Objective: Win two battles against the Skaven.

Description
The Moon Staff is imbued with the immortal power of the Goddess Lileath, eternally youthful daughter of Isha.

Lore Background
''The Moon Staff is imbued with the immortal power of the goddess Lileath, eternally youthful daughter of Isha, which flows through Teclis and invigorates his feeble frame. In times of great need, Teclis can call upon the full power of the staff. Doing so allows him to unleash a fearsome barrage of magical power, or else dissapate dangerous sorcerers energies before they spiral out of control, but also leaves Teclis himself badly weakened.''

Outdated
Previously it was a hidden legendary item. It was unclear exactly how to trigger the quest for it. It may have appeared as a random drop after a battle, similar to the Stone of Midnight. Or it could have required the player to have completed the fourth ritual in Eye of the Vortex and be at war with a Skaven faction.

Source

 * ItalianSpartacus YouTube video