Some investigation and divination reveals...
Soul Totem --
A bearer of a piece of the Soul Totem, if wearing it as an amulet (i.e. it uses up the amulet slot), can use the spell Plane Shift (6th level Shaman spell) if in the material world -- and any Teleport spell if in the Spirit World -- to get to a point within a Positive Energy region of the Spirit World about 5 miles from where the Bastion of Unborn Souls is located, and once there, can travel unerringly to the Bastion and its single entrance.
A bearer of two pieces of the Soul Totem also gains the benefits of one positive level.
A bearer of all three pieces gains the benefits of three positive levels instead of only one. However, bearing the completely assembled Soul Totem causes great concern amongst the Celestial Court, which may send agents to slay the wearer if necessary and to disassmble and disperse the pieces of the artifact.
Positive Energy Regions --
While digging around in the Cathezar's notes looking for clues and further useful tidbits of info, references are come across mentioning a spell "Positive Energy Protection". According to the Cathezar's notes, this spell is not widely known of, but may be available to shamans who petition their Spirits for it, if they truly seem to have a need for the spell.
It is a mere 3rd level shaman spell which taps into negative energy to protect against positive energy. One standard action to cast, range touch, target = creature touched, duration is 1 round per level. Will negates ("harmless"), and SR applies normally.
The creature warded by the spell gains partial protection from the effects of positive energy, including magical healing and regeneration. (As healers, the very concept of "protection against healing" rubs many shamans the wrong way -- but those who deal in undead may well petition sinister spirits for this spell.)
The primary use of the spell is to protect creatures from positive energy effects -- it allows a d20+caster level check against a DC of 11+HD of the effect's originator, if successful the negative energy of the spell negates the positive energy effect with a roiling ball of darkness and a thunderclap -- the positive energy effect does not occur and if the originator is touching the warded creature it takes 2d6 points of damage. If the level check fails then the positive energy effect works normally. (Note that this includes someone trying to cure or heal the warded creature.)
For the purposes of this group, a more useful facet of the spell is that it offers protection against the blinding effect of Positive Energy regions and also prevents the creature from gaining temporary hit points for its duration, or getting Fast Healing 5...
Other notes indicate that the effects of the Positive Energy regions can be negated in other ways -- the Cathezar not having been a shaman herself -- such as by tying a blindfold across the eyes (to avoid having to need Fortitude or be blinded) and arranging to deal damage to oneself on a continuing basis. The Fortitude DC of the blinding effect isn'r very high (DC 15) but anyone can be blinded eventually (roll a 1) without some sort of protection. Fortunately the blindness is only temporary (lasts 10 rounds), but assuming the creature then closed its eyes until the searing light in its head seemed to diminish, when it wears off the creature must start resisting again. Meanwhile, the physical dangers of the positive energy are better understood after reading the notes -- creatures gain fast healing 5 when there, and those at full hit points gain 5 temporary hit points per round -- but any round that a creature has more than its normal maximum hit points it must make a Fortitude save (slightly tougher at DC 20) or explode from excess life energy...killing and utterly consuming the creature.
Hmmm...
Also, any spell which utilizes positive energy (such as all healing spells) are automatically maximized within the region, and turning attempts against undead gain a +10 bonus on the roll to determine effect; Fortitude saves to negate negative energy effects are at +10 also.
And that is it for now I think...
-- E3 / DrakaraGM