Tomb Tainted Soul, vs Negative levels.

[Yogibear41]

Normally a character would use a Death Ward type effect to protect himself from negative levels, however a character with the tomb tainted soul feat generally uses negative energy to heal, but otherwise has no protections from negative levels. What is the best way for a character with the tomb tainted soul feat to protect himself from negative levels, without also losing the ability to heal from inflict spells, the harm spell, or similar?

Or should a character who has the tomb tainted soul feat also benefit from negative level dealing abilities similar to an undead creature would gain temporary hit points from enervation like effects?

[NontheistCleric]

Or should a character who has the tomb tainted soul feat also benefit from negative level dealing abilities similar to an undead creature would gain temporary hit points from enervation like effects?

This wouldn't happen. Tomb-Tainted Soul states 'You are healed by negative energy and harmed by positive energy as if you were an undead creature', but gaining temporary hit points is not healing.

Some feats you could take to protect yourself from negative levels include:

Font of Life (Heroes of Horror), which allows you to make a saving throw to avoid negative levels altogether,

Enduring Life (Libris Mortis) which allows you to ignore negative levels for a number of minutes equal to your Con modifier, and

Lasting Life (Libris Mortis, requires Enduring Life and Endurance), which allows you to take a standard action at any time to attempt to remove negative levels. You can even do this repeatedly if you fail.