Looking for a template

[G.Cube]

to represent a creature infected,adapted, or otherwise effected by the Positive Energy Plane.

[Guyver87]

There is a Template called "Vivacious Creature" from the Planar Handbook, that would probably be exactly the thing You are looking for.

It changes the character into Extraplanar Outsider, and makes him Incorporeal. He also gains flying, with perfect maneuverability, deflection bonus to AC equal his Charisma modifier (But loses all forms of Natural Armor), Fast Healing 5, aura healing everyone around it (Or harming the Undead), as well as an ability to shot rays of Positive Energy.

Additionally character gains enhancement to Attributes (+2 to Con, and Cha), Spell Resistance 15 + HD against spells based on Negative Energy, and does not "overload" on the Positive Energy Plane.

Problem is that character with that Template loses his Strength, as an Incorporeal being, and because of that can't make physical attacks.

And this Template has LA +5, so it's quite costly...

Nevertheless I hope it would be of some use to You.