I am tired, and this may not make a whole lot of sense, so please work with me.
Give him armour covered in bones of some sort.
The first time he is hit with something that causes him to bleed, have him give an evil smile and shout a command word of some sort.
Every time he gets hit after that, bones fly off and, a round later, a skeletal minion pops up. Once he gets bloodied, increase the level of the minion that comes off.
If you really want to be cruel, if he takes damage from a fire/cold/force/etc spell, have the skeleton come to be with a blazing/freezing/force aura of some sort.
Give him armour covered in bones of some sort.
The first time he is hit with something that causes him to bleed, have him give an evil smile and shout a command word of some sort.
Every time he gets hit after that, bones fly off and, a round later, a skeletal minion pops up. Once he gets bloodied, increase the level of the minion that comes off.
If you really want to be cruel, if he takes damage from a fire/cold/force/etc spell, have the skeleton come to be with a blazing/freezing/force aura of some sort.
