You are able to sense the presence of creatures infused with negative energy, and can temporarily embrace it yourself.

Prerequisite: Crysalin with the negative affinity racial trait, character level 3rd.

Benefit: You can use detect undead as a constant spell-like ability (caster level equals your total level). In addition, once per day as an immediate action, you can treat positive and negative energies as if you were an undead creature, taking damage from positive energy and healing damage from negative energy. This ability lasts until the end of your next turn.