There are indeed two, very fun ways to go about this spell, and maybe they should be two different spells. The one I need for my next session will be used specifically for shock value. The vision of recently-slain foes rising as undead to fight again is playing in my mind alongside the shocked looks on my player's faces.
I don't care how long it takes to cast the spell--my evil orc cleric is going to cast it on his followers before battle is joined. What I do need is nearly instant results. How about:
1d3 rounds after the subject is slain, it rises as either a skeleton or zombie (as though it had been the subject of an animate dead spell).
I also propose that this form of the spell require a Will save to resist, as willing zealots in the evil cleric's flock will voluntarily fail their save.
The other form, which I don't need, but is equally cool, is the curse of undeath. This one could even be the plot hook of a horror adventure where the dead rise every night after burial. Maybe a town recently inflicted with plague or some natural disaster hires the PCs to investigate.
So lets try this:
Rise Again
Necromancy (Evil)
Level: Sor/Wiz 6, Clr 4, Death 4
one could argue one or two levels higher for the added delay function, but its only more useful because you do not have to cast animate dead in the middle of combat
Components: V, S, M, (DF)
Casting Time: 10 minutes
Range: touch
Targets: one creature per level
Duration: instantaneous
Saving Throw: Will negates
Spell Resistance: Yes
You can make subjects doomed to rise as skeletons or zombies (your choice) 1d3 rounds after they die. If the bodies are completely destroyed by the death or in the minutes immediately after, the spell has no effect. In addition, raising or resurrecting the corpse before this spell is triggered does not invalidate the spell, it simply pushes its function back.
This spell can not be dispelled normally, although a remove curse cast by a caster of a level at least equal to yours can end its effect but only after the target's death. A wish or similar spell can remove the spell completely. I like this part--I imagine a party cleric hastily casting remove curse before his fallen companion's corpse is desecrated by the negative energies of undeath!
Material Components: The material component of this spell is black onyx dust and ink worth at least 100 gp which must be tatooed on the target when the spell is cast.