Lantern of shadows
|An unholy device which calls forth flickering shadows to assist its wielder. It shrouds the wielder in unnatural darkness, making them unstealthy and significantly reducing the power of their spells.|
Unlike most of the miscellaneous items, the lantern of shadows is not evoked; it is activated whenever it is wielded as a "weapon". When wielded, this sinister device will dim the natural light of the dungeon around the user, erasing all colours and reducing his or her line of sight (and the monsters' as well) by 2 tiles. This gives you 6 tiles from the usual 8 tiles. This stacks with other sources of LOS reductions (like Nightstalker mutation or the Darkness spell).
In addition, neutral shadows will begin to spawn from the lantern, and be attracted to flutter around it like moths until they expire. The good gods take this as Necromancy. Okawaru does not like it when they are destroyed. The shadows will remain (and stay friendly) for a while after the Lantern is unwielded. The shadows follow you around levels, making this item ideal for exploring new stairs.
The lantern also works as a double negative spell enhancer ("extremely numb sensation" if unenhanced). That is to say, it would cancel the effects of two rings of fire if you tried to cast a fire spell while wielding it. (Obviously, you can't combine it with a staff!)
Stealth is set to 0 (extremely unstealthy) if you're wielding a Lantern of Shadows. While in use your MP are drained with every shadow appearing until you run dry.
This item is finnicky, to say the least. In exchange for reduced LOS and friendly shadows constantly surrounding you, you will have impeded melee combat, impeded spellcasting, and no ability to sneak up on monsters. Mostly these lanterns can be useful for escape: the reduced LOS will help you leave monsters behind (remember, they can't see you if they're beyond your LOS), while the shadows can help cover your retreat. Don't expect the shadows to kill much - they're outclassed by the later levels of Lair.
Prior to 0.16, lantern of shadows didn't drain MP while in use, and didn't cease to function once its wielder runs dry.
Prior 0.9, an unidentified lantern of shadows always appeared as a bone lantern.