I believe the spell you are looking for is Fortunate Fate out of the Spell Compendium(latest version of the spell anyway). It is Cleric 7 and can be cast on any living creature. It lasts 10min/lvl or until discharged. If the subject is killed in a way that a Heal spell can repair, a Heal spell is triggered on him/her/it and the target doesn't actually die(receiving the full effects of the Heal spell). It is not the same as a contingent Heal and there are no apparent limits to the number that a creature can have active on them. It would seem reasonable(to me, anyway) that if more than one are active they would all go off at once upon a single triggering instance. That is after only a few minutes of thought about it though. I hope that helps.