If you exceed the overflow of the vessel, the shedim is disrupted, and is NOT coming back anytime soon...
BUT: Keep in mind, this is not really as easy as it sounds... the vessel is dead.... D.E.D, Dead. A bullet isn't going to make it more dead 😜
Time to think beyond "Moar lead NOW!!" and dig a little deeper into the tool box.
I guess I disagree; in my opinion, guns'n'bombs will still do damage to a corpse.
Possession (SG p.197) has some information that could be interpreted to suggest that a corpse's physical attributes are used (italics mine):
"
Dead/Inanimate Vessels: While possessing a nonliving vessel,
the spirit adds half of its Force to the vessel’s Structure and Armor Ratings (p. 197, SR5), Object Resistance dice pool (p. 295, SR5), or
Physical attributes, depending on the situation and/or vessel type."
and later (italics mine):
"
Damage:
If the spirit or the vessel has already sustained damage, that damage sticks around upon successful possession, but only the greater set of the combined Wound Modifiers applies (modified by the spirit’s Force, for living vessels). Physical damage incurred during possession is recorded as a single track, and both vessel and spirit retain the full amount of this damage when possession ends, which is cumulative with any previous damage. When possession ends, the vessel’s Physical attributes return to normal while the damage stays in place, so this damage can have potentially lethal side effects."
So, I could see starting with "what was the CM of the corpse when it died?" If the Shedim can't regenerate (say its a F5 Shedim and didn't take it as the optional), it possesses a corpse and adds half its force to the corpse's attributes. If the corpse-in-life had Body 4, physical CM 10, its overflow is 14. Let's say the corpse died from getting shot fulla holes and starts at 15 boxes down. If a F5 Shedim possessed it, its new body is 4 + F(5)/2 = 7 (rounding up). It's new CM is then 12 (rounding up), its overflow is 19. So, just jumping in, it's an animated corpse, shot fulla holes, looking pretty damn ragged (4P to give on its CM). Shoot it fulla a few more holes to fill the CM to 20, it's "dead" again, and the spirit is disrupted.
If that corpse got "overkilled" (say it starts out at 20 boxes down) it may be "too shot fulla holes" to be possess-able in the first place (after possession it would still be past overflow limit).
Of course, if that Shedim *had* regeneration, well, it's going to quickly regen and be back in good shape with a CM of 12, overflow 19, dead @ 20. BUT I'd need to do enough physical damage in a combat turn that its regen won't get it under 20. Average regen would be hits on 5+7=12 dice, call it 4 hits, plus body of 7, for 11. So I'd need it, at the end of a round, to be at about 31-32 physical damage, on average, to truly "die" and get disrupted (yikes!).
Another possibility is that this corpse died from "natural causes," in which case the CM might be zero boxes to start. Or maybe the unfortunate "bled out" from a slit throat (called shot to neck, R&G p114) or other rules and I might house rule that the CM resets to the actual damage, removing the bleed-out DV that a Shedim might not be bothered by. Corpse might still be beat up, but not as bad as "shot fulla holes."
Also, keep in mind a shedim can abandon a vessel that is useless, in favor for a better vessel if one is near by. (hence the "don't fight in a graveyard), so blowing the limbs off a corpse might stop it from trying to eat you, but it doesn't stop the Shedim from just jumping to a corpse WITH arms and legs...
I agree, I don't see anything that suggests a Shedim
can't freely abandon a vessel. BUT, it would do so at its own peril. Back to Possession (SG p.197, italics mine):
"
Damage:
If the spirit or the vessel has already sustained damage, that damage sticks around upon successful possession, but only the greater set of the combined Wound Modifiers applies (modified by the spirit’s Force, for living vessels).
Physical damage incurred during possession is recorded as a single track, and both vessel and spirit retain the full amount of this damage when possession ends, which is cumulative with any previous damage. When possession ends, the vessel’s Physical attributes return to normal while the damage stays in place, so this damage can have potentially lethal side effects."
Though the example in the text focuses on the danger to the physical vessel, the Shedim is in just as much peril. Let's say a F5 Shedim, same as the example above, has taken 12P on its CM, and decides to ditch the vessel. When it separates, the damage is retained, but is now measured against its own attributes. It's got a Body of 5, so its CM is 11. Flipping to the section about Disruption (SG p.192):
"When Physical or Stun damage fills up a spirit’s Condition Monitor, that spirit is disrupted and immediately returns to its native metaplane."
Thus, boom, the moment it fled, it dead (or, disrupted, as it were), because it has 12P and its CM is just 11. Also, fleeing at, say, 10P, only really makes sense if it was purely running away. Back to Possession (SG p.197):
"Damage: If the spirit or the vessel has already sustained damage, that damage sticks around upon successful possession, but only the greater set of the combined Wound Modifiers applies (modified by the spirit’s Force, for living vessels)."
Thus, merging with another vessel, even a "pristine" dead body, would put it essentially right back where it started: 10P on its CM. The flesh is willing, but the spirit is weak, as it were.
A lot of this hinges on assessing a corpse as using its physical attributes and CM as I have done in my examples above. If you treat a corpse as a barrier with structure and armor, it'd pan out differently. That said, the physical attributes feel more "right" to me, and a shot fulla holes corpse is still shot fulla holes, even if it has been possessed (it just has a little bit more "go" left in it, from the possessing spirit).