Myrkul's Book of Shadow describes a ritual that binds a creature to a candle flame.
Through a blood ritual you bind your soul to a candle fire. The candle's magic is activated when the candle is created, it begins burning on its own. The candle can't be snuffed out by any non-magical means unless the life source of the candle dies.
The candle fire is magical and doesn't burn or emits heat. While lit, the candle sheds dim light in a 20-foot radius. It grows brighter or dimmer based on how stronger or weaker the life source it represents gets.
Only death causes the candle flame to die out, travelling to other planes does not. Only if a create dies or becomes undead does the candle flames goes out.
If a Warlock or Priest of Myrkul dies and had previously cast this spell, if its body is not destroyed, the creature can be revived by lighting up the candle with fire on top of its dead body and sacrificing another creature before the candle finishes burning, once the creature is revived this way, the candle is then destroyed.
If someone uses Dispel magic or anti-magic on the creature it does not affect the candle's magical effect, if someone uses Dispel magic or anti-magic on the candle the candle's fire is snuffed out and the candle is destroyed.
* - (A candle made from blood (must be from the creature it is being bound to) and diamond dust worth 1,000gp.)