Curse of the whispering dead

"Legend tells of a secret necromantic spell which allowed the great necromancers to communicate with each other. This, allowed them to coordinate a strike upon the Holy King's forces, ending the great holy war"

The caster summons his necromantic powers in order to form a direct link with an object, allowing for a direct voice communication between the caster and the player holding such item. The item serves like a low volume speaker, emitting a mildly low sound during speech. The item transmits any sound from up to a 3 foot radius, and can be heard by any creature on a 3 foot radius. Communications can be severed by the caster or player by removing the blood, but can only be turned back on by the caster himself using a drop of blood. The item does not have a sound filter, for which everything can be heard. While different items can be casted and given to different players, only the caster can hear the players, but all the players holding the item can hear the caster. The caster can select one player to hear from.

At level 2: Communication range, 2km

At level 4: Communication range, 4km

At level 6: Communication range, 8km

At level 8: Communication range, 16km

At level 10: Communication range, 64km

At level 12: Communication range, 200k

At levle 14: Communication range, An entire nation

At level 16: Communitacion range, No Limit

Sound filter is developed when the player reaches level 5, allowing only the voice to be heard, and preventing enemy creatures from hearing any sounds made by the item.

Each level adds half a day to the spells duration

At level 10, all players can hear each other, but only the caster can select a voice

At level 15, all players holding an item can select a voice

Being a spell belonging to the necromantic arts, Paladins or creatures with a holy pact can only use this item by suffering 1 damage per hour. Health points lost by this effect cannot be regenerated while holding the item. 

Letting go of the item will cause it to lose its effect. After the spell is done, the item is consumed.