Owning this resource allows access to the Death sphere spells, Raise Skeleton, Summon Spectre, and Summon Wraith. It also causes diplomatic penalties with many leaders. Creating undead units hurts relations with both the Mercurians and Sidar leaders.
Arcane units can get Death I for free if their owner controls two sources of this resource at the time they are trained or upgraded. Those with Channeling II can get Death II for free if their owner controls four sources, and those with Channeling III can get Death III for free if their owner controls five sources. Vampirism can also let a unit get the first two level Death promotions. Units that did not get these promotions for free can still purchase them with experience points if they have the prerequisite promotions and their owner has at least one source of the mana.
The Sidar represent the sphere of Death, but they do not have the normal advantage of getting the first level of their patron's sphere for free like most civilizations do. In fact, their Shrine of Arawn unique building removes Death promotions, grants Undead Slaying, and causesif they have a source of Death mana.
Death magic in Erebus is actually Undeath magic, a terrible deviation from what the Death sphere is supposed to represent. The Undead are created by magic that binds the souls of the departed to the world of the living. This is extremely unhealthy both for them and the world around them, leading to much corruption.
The precept of Death is about surrender and resignation, intended to balance the perseverance of the precept of Life. It is the rest for which a soul longs once it is weary of the world. It allows the old to get out of the way and to make room for the new. During the first few generations of man, death was rare and almost always welcome. The widespread fear of death today is a sign of the world's corruption.
Arawn was always very dour, but benevolent. He shelters the souls of almost all of the departed, never manipulates them into serving his purposes, and won't even reward or punish them. His Netherworld is a vast dreamland, where the subconscious of each mortal soul fashions the sort of afterlife it believes itself to deserve. This is usually more fair than any reward or punishment any outside authority could devise, but there are a few strong souls whose lucid dreams grant them undeserved power. The archmage Laroth is building an army of such souls in the hope of usurping the precept and becoming a god.
The Sidar hate Death magic, as does the God of Death. Arawn chose to withdraw himself completely from Creation in order to prevent sorcerers from channeling mana from him. (Death mana is now instead channeling from the Gem of Creation which Tuoni stole from Agares.) This decision has angered many of his servants, who have abandoned him to follow either his former archangel Basium or the rebel Laroth. Few of his loyal archangels care enough to help the archangel Gyra defend the realm.
