Ok I'm putting all of the suggested powers on one post, as more are made up I will edit this to add them. Tell me if I missed one.
Shadow Rejuvination: By drawing shadow essence from the plane of shadow, ________'s can regenerate themselves, giving them regeneration 5 but they are delt normal damage by positive energy or good, also, this ability only functions if the ________ is in partial or total shadow
Hunt: The _________ operates under a continuous deathwatch affect in a 120 foot radius. This allows the __________ to hunt down and find an opponent in underground or urban settings as well as target weak opponents to eliminate first.
Negative Energy Overflow: The damage caused by the skulls is from all off the negative energy the skulls give off. It follows the same rules as swarm damage but causes the damage to be negative energy not physical damage. This also has the side effect of curing undead if in the same square as them.
Damage Reduction 10//Magic and Good
Unholy Toughness: This gives it charisma bonus to hp rolls, since it doesn't have a constitution this will help its life out.
Negative Energy Taint: Any spell that uses positive energy cast within 60 feet of a _______, uses negative energy damage instead of positive energy damage. This causes it to harm living creatures and heal undead creatures. (If this is to powerful we could change it to do 50%, that would effectively negate it.)
Flight: A ________ has a fly speed of 60 ft, perfect
Life Siphon: A ________ can drain 5d8 hitpoints from an undead creature as a standard action. This heals the _________ by equal amount of damage. (Basically the creature siphons off a part of the undead's negative energy to charge itself.)
Spell Like Abilities: Harm 1/day, Enervation 3/day, Death Knell At will, Control Undead 3/day
Maddening Babble: The muttering and chattering of the skulls confuses anyone trapped in their midst. Any creature caught within the swarm at the beginning of their turn must make a Will save (DC 20) or be affected by the confusion spell. DC is Charisma based.