I am wondering if that works equally well for free-willed undead as for those of the mindless persuasion.
Looking at the list of conditions there I could totally see an enraged or frenzied vampire and while they might have an easier time shaking it off I think it would be cool to allow the frightened, and terrified conditions as well.
Maybe there could be an Undead quality that covers some of the classic things about undead but then for zombies, skeletons and other shambling corpses use the Constuct quality because really a zombie is just an undead construct anyway. And then create other/use other quality to cover the bases for other undead baddies.
And of course then I check Spellbound Vol I and find(I have seen this done before but if quoting from the books is frowned upon feel to remove it or ask me to):
Undead (+5 XP): The character is a supernatural force clothed in the physical or spiritual remains of a once living creature. An undead character possesses the low-light vision and light-sensitive NPC qualities at no additional cost. Further, he is immune to Constitution damage, critical hits, subdual damage, stress damage, diseases, and poisons, as well as the paralyzed, sickened, and stunned conditions.
An undead character is also immune to bleeding, internal ruptures, brain damage, massive system trauma, and nerve damage as described on Table 5.5: The Table of Ouch (see the Spycraft 2.0 Rulebook, page 332). Whenever one of these results is rolled for an undead, the character instead suffers the next highest result to which he is not immune (i.e. a bleeding result becomes a broken limb, an internal rupture result becomes a maimed limb, and a brain damage, massive system trauma, or nerve damage result becomes a spinal injury).
An undead character doesn’t heal naturally but may benefit from Medicine skill checks. Healing caused by spells with the Light descriptor instead inflicts the same amount of damage to him, while damage inflicted by spells with the Darkness descriptor instead heals the same amount of damage he’s suffered. An undead character’s wound points may not be negative; should they ever drop below 0, he immediately dies.
An undead character need not breathe, eat, or sleep, but may feign doing so if he likes.
Finally, a special undead character can often pass as the once-living person whose body he now inhabits, and gains a +10 bonus with Falsify/Disguise checks made to masquerade as this person.