[Twan]

Death has some better AE spells costing 0 gem in higher levels if you can have D4 or more powerful mages. Namely the two cloud spells, Cloud of Death and Leaching Darkness. Their precision is low and they often kill some of your own troops but they offer a good synergy with the spam of skeletons, as your undeads are totally expandable and their numbers should block your ennemy in the clouds. Their fatigue cost is so small you can easily cover all the front with 2 D4 mages.

There is also disintegrate usefull to kill ennemy thugs or high hp units, when you reach alteration 8 (of course if you have astral mages rather search thaum 5 for soul slay).

But the main strength of death on the battlefield is the battle enchants like Darkness (all ennemy archers become useless, and living ennemies without darkvision become crappier troops than your undead chaff), and Rigor Mortis (unresistable fatigue for all non undead being).

There is also Bone Grinding (3 dammage to all units on the battlefield + a possible "crippled" affliction) very good if your own troops are ethearal like ermorian vestals (as it's mundane dammage they have 75% chance to resist) or if you have a powerful air mage to cast fog warriors on your army (your troops take 1 dammage per cast of Bone Grinding, when the ennemies take 3).