Life Pact

You bind the life forces of the targets into a mystical pact. If any target is reduced to fewer than 0 hit points, that target automatically triggers the power of the pact. The triggering target drains 1 hit point from all other targets who have at least 1 hit point and are within 30 feet of the triggering target; these hit points are applied to the triggering target as magical healing. This healing can prevent the triggering creature from dying, if the attack would cause the target's to have an amount of negative hit points equal to its Constitution score. This healing cannot raise the triggering creature above 1 hit point; any excess hit points drained from other targets are wasted. The pact can be triggered once per round. It's not triggered by death effects or effects that do not deal hit point damage.