Source: Dragon #358
Your connection to the Positive Energy Plane and the forces of life itself allow you to turn your familiar into a living vessel of light and energy.
Prerequisite: Good alignment, ability to summon a familiar.
Benefit: As you advance in levels you gain a number of additional abilities when interacting with your familiar. These abilities are in addition to those normally granted to or your familiar. At 1st level, you can, at will, order your familiar to glow as a free action producing light equal to a torch. Beginning at 5th level, you can once per day, touch your familiar and channel a surge of positive energy that heals it for 1d6 points of damage + 1 per class level. This requires move action. At 9th level, you can, once per day, convert your familiar into pure positive energy for 1 minute. During that time, your familiar emits positive energy in a 20-foot-radius emanation. Undead within the emanation take 1 point of damage per round, while living creatures other than you or your familiar gain fast healing 1 while within this aura. After producing this emanation for 1 minute, your familiar disappears into the Positive Energy Plane for 24 hours, during which time you gain no benefits of having a familiar. Activating this ability is standard action. Beginning at 13th level, your familiar's loyalty and devotion, when coupled with its connection to the Positive Energy Plane, allows it to sacrifice itself to save your life. If able to reach your body within 1 round of your death, your familiar can unleash conflagration of positive energy that consumes it utterly but returns you to life, stable but at -1 hit points. You suffer none of the ill effects that normally come from returning to life (including level loss), but you automatically lose the full 200 XP per class level for the death of your familiar. Due to the special nature of its sacrifice you can summon a new familiar after waiting only one month. At 17th level, you and your familiar gain fast healing 1 as long as you both have at least 1 hit point and are within 5 feet of one another.
Special: Whenever you cast a spell with the darkness, death, or evil descriptor you lose access to all benefits of this feat for the next 24 hours. A wizard may take Wedded To The Light as a wizard bonus feat.