Okay, here are the mechanics I have so far:
Necromantic Energy Construct: XXXXX are a very unusual energy construct that is designed to imitate normal life. This gives them some very unique qualities:
- Low-light vision.
- Negative Energy (such as an Inflict spell) can heal a XXXXX. However, spells that would normally heal through the use of Positive Energy (such as a Cure spell) deal damage to a XXXXX.
- Unlike normal constructs, XXXXX can heal damage on its own
- XXXXX have a Constitution score.
- XXXXX do make Fortitude saves.
- XXXXX are subject to ability damage, ability drain, fatigue, exhaustion and energy drain.
- XXXXX do not breathe or eat, but they do enter a cycle of necromantic “sleep”. Their sleep cycle helps the XXXXX keep their form.
- XXXXX can be raised or resurrected.
Medium: XXXXX are Medium creatures and have no bonuses or penalties due to their size.
Normal Speed: XXXXX's have a base speed is 30 feet.
Necromantic Phasing: For a number of rounds per day equal to your character level plus the modifier of your chosen mental ability, you can melt into pure Negative Energy, becoming slightly incorporeal. Entering or exiting this state is a free action. Necromantic Phasing has several effects, as follows:
- You only take 1/4 (25%) damage from non-magical weapons. However, you take full damage from all magical weapons, spells, and spell-like abilities.
- You can enter or pass through solid objects, but must remain adjacent to the object’s exterior, and so cannot pass entirely through an object whose space is larger than your own. You can sense the presence of creatures or objects within a square adjacent to your current location, but enemies have total concealment (50% miss chance) from you. In order to see beyond the object you are in and attack normally, you must emerge. You have total cover while inside an object, but when you attack a creature outside the object you only have cover, so a creature outside with a readied action could strike at you as you attack. You cannot pass through a force effect.
- If you hit with a touch attack or unarmed strike, you deal one point of Negative Energy damage. The damage from this ability cannot be used to heal yourself or any other XXXXX.
- Your insubstantial feet and equipment make less noise as you move around. Anyone trying to use a Perception check to hear you takes a -2 penalty.
- While phased out, you can take a +2 bonus on any Knowledge check. This represents you using the knowledge of the inhabitants of the planar crack to supplement your own. A Knowledge check taken with this bonus requires a full round action.
I moved the blink functionality from your initial notes into a feat. However, since they don't actually go between the Material and Etherial Planes, the random chance mechanic doesn't really make sense. I was thinking we could replace it with a Will save that increases as they travel through more spaces. As a rough outline:
While phasing, you can step through (but not see through) solid objects. To pass through the first 5 feet, you must pass a DC 16 Will save. For every 5 feet you pass through, the Will save DC increases by 2. If you fail any save, you are shunted off to the nearest open space and take 1d6 points of damage per 5 feet so traveled.
Another major thing I changed was how you activate the Necromantic Phasing. I changed it from a times per day system to something akin to the new Barbarian rage system. I like the rounds per day a lot more. It allows you to be much more flexible and tactical with your power.
So what do you think of this? Let us know!