[Taqwus]

Life drain attacks inherent to monsters -- ghosts, vampires, horrors, et al -- are generally melee-only. The life drain spell, on the other hand, has some range. Wielded against undead, neither provides the usual healing and reinvigoration side effect.
Ghosts are not terrifically strong against undead, particularly undead with magical attack forms since the magical weapons ignore etherealness. I'd probably prefer undead archers, for their ability to hit the undead masses before meleeing, and since banefire arrows are conveniently magical; it might be possible to do fire-and-run attacks with them.