Best Bet

[Bone Armor] was yet another simple technique as fundamental as [Corpse Explosion]. But, once again, to a Summoning Necromancer, especially one with Skeleton Warrior or Skeleton summons in general, with the added flexibility of such summons, it could be used almost too freely. 

[Bone Armor] had a few applications. The first was in using the self healing properties of Skeleton Warriors to instead cause outgrowths. These outgrowths, almost like tumors, would result in excessive bone material that could be used in various ways, the best of which would be as an armor. 

A second method of using [Bone Armor] would be to sacrifice an entire Skeleton Warrior to become the armor for a second Skeleton Warrior. This application was even more potent than the first and more efficient as well, though it required a complete sacrifice.