The Forbidden's player got back to me regarding my build. He said that ideally the character would have a few more skills and a couple ranks of Clinging (from his "probes"), but otherwise it looks great. I thought I'd post as-is, with the understanding that if he does ever turn up he would likely be tweaked a bit.
Here is...
The Forbidden (PL 12)
Real name: John
Age: Unknown, perhaps mid-thirties?
Abilities:
Str: 18 (+4) Dex: 16 (+3) Con: 14 (+2)
Int: 14 (+2) Wis: 18 (+4) Cha: 10 (+0)
Fortitude: +2 Damage: +4 Reflex: +3 Will: +6
BAB: +9 BDB: +9
Attack: +15 melee, +14 ranged, +15 mental
Defense: 22 (19 flat-footed), 23 mental (21 flat-footed)
Skills: Bought 2:1. Hide +8, Knowledge (Occult) +4, Move Silently +8
Feats:
Darkvision
Detect Auras
Heroic Surge
Improved Critical
Improved Grapple
Improved Pin
Instant Stand
Iron Will
Power Attack
Psychic Awareness
Rapid Strike
Takedown Attack
Toughness
Powers:
Mental Protection +10 (2 pp/rank in this campaign) Source: Psionic (Council-trained? See below.)
Flaw: Duration: Sustained
Solidified Aura +10 (6 pp/rank) Source: Psionic (Council-trained)
Force Field (all the other powers require the Force Field to be up)
Extra: Subtle
Extra: Immunities (Cold, Darkness, Electricity, Fire, Gravity, Kinetic, Magnetic, Radiation, Sonic, Vibration, Critical Hits)
Strike
Life Leech (Drain)
Extra: Slow Recovery: 1/min. Usually his victims don't survive, but this is also the rate at which he loses drained Con for purposes of "burning".
Extra: Duration: Concentration
Flaw: Full Effect
Flaw: Limited: Constitution Only
Psychic Manipulation (Variable Effect)
Extra: Mental
Extra: Subtle
Flaw: Range can be no greater than Touch.
Flaw: Tiring (But the Forbidden can avoid the fatigue by "burning" 1 point of drained Con per rank of power used.)
Power Stunts:
Devour Magic (Neutralize)
Extra: Neutralizing Block
Extra: Neutralizing Field
Extra: Nullification
Flaw: Range: Touch
Flaw (2): One Source - "Magic" (Council-trained Psionics)
Healing
Extra: Regrowth
Extra: Triggered by unconsciousness
Flaw: Self Only
Flaw: Burns Con. The Forbidden must "burn" one point of drained Con for each rank of Healing used, much like the Healing feature of Absorption.
Dual Damage (for Strike)
Extra Reach: The Forbidden can extend "probes" from his aura to attack others at a distance. Treat each stunt as granting 5' extra reach. [I base this on Elasticity Flawed down to only give extra reach - 2 pp/rank. Add an Extra for "only requires a free action" and a Flaw for "base stretching movement only" - ie, no "sprint speed". You can probably get the same result from Growth if you work at it. I suppose I could buy this as a partial Extra, but somehow it feels more natural as a stunt.]
Weaknesses:
Hunted (5 points)
The Forbidden is being actively hunted by the Council, who earnestly wish to see him destroyed.
The Hunger
The Forbidden loses one point of Constitution per day. He can restore these lost points only via his Life Leech power - he can "burn" 3 points of drained Con to restore one point he has lost as a free action. It is very difficult for him to refrain from draining somebody to the dregs once he starts - it takes a Will save vs. DC 20 to do so.
If the Forbidden's Constitution ever dips to half its normal value or less, he must make Will saves each hour at DC 15, +1 for each hour past the first. If he fails, he goes berserk and will drain the nearest available targets dry until completely sated. (He has never permitted himself to reach this point since he learned, the hard way, what would happen if he got hungry enough.)
Background:
For centuries, the world's history has included a hidden layer that never made it into the textbooks... and for good reason. Any who discovered the truth either had a vested interest in keeping it hidden, or else had the good sense to keep quiet, or else were forcibly silenced. The Council does not look kindly on meddlers save for themselves.
Governments, armies, churches, secret societies - all were but pawns in the elaborate games of the Council, as they jockeyed for position, for knowledge, for power. For they alone (to their knowledge) had perfected the secrets of honing and tuning the psionic powers that lay dormant in the minds of so many. They had learned to control the "aura", the mental field projected by all thinking beings - how to reach out with it to touch the minds and hearts of others... or to make it solid, tangible, and deadly. The greatest among them - the Masters - could use it to manipulate their bodies' aging processes and live many lifetimes.
Yet though they saw themselves as above the concerns of the unwashed, blind mortals surrounding them, there were things that even the Council feared. Among these were the Forbidden - so called because their most ancient lore warned in direst terms against ever training those rare people with unusual, reversed auras - auras that seemed to absorb life and light rather than projecting it. Untrained, the effect was so minor as to be negligible, a curiosity, no more. None knew what the threat of the Forbidden was, but one of their few ironclad laws forbade them from finding out... Until Peerless.
His chosen Council-name reflects the arrogance of the man. In his lust for power over his fellow man, Peerless acknowledged no boundaries, not even the Council's most ancient laws. It made him a dangerous man - but a foolish one. For, hoping to create an assassin that none of his fellows could face, Peerless found, manipulated, and took on one of the Forbidden as an apprentice. But in a routine training exercise, his catspaw's dark powers awoke and snuffed out his life quite accidentally - the life of one of the greatest Masters!
The others knew terror of one not of their own for the first time in centuries, perhaps longer. A man capable of destroying one of them was an unendurable threat - yet they dared not face him themselves. They sent apprentices and other agents to kill him, to no avail. He drank up their power and then drank up their lives... then fled untraceably. They still search for him frantically, the one they now call THE Forbidden - the only one with the knowledge to harm them.
When he solidifies his aura, those with eyes to see perceive him to be swallowed up in its glistening, impermeable blackness - blackness he can extend as probes to rend and tear, or to fasten like leeches in the aura of another, to drink deep of life. Probes that can tear the auric constructs of Council-trained psychics to pieces. He has not mastered the Council's techniques for altering the minds of others by aura-touch (and his reversed aura makes it difficult in any event) but he can manage some tricks with effort.
The Forbidden remembers little of his past - it is standard practice among the Council to mindwipe their apprentices to make them more loyal and dependent on their masters. He is a large man, and skilled in fighting even without the formidable edge his powers give. Yet he is a sensitive soul who loves to read the classics and walk in the mountains - one who seeks peace away from his fellow men. He hates what he must do to survive with all his being, yet he cannot bring himself to die when he knows he is the only one who can disturb the Council's peace and distract them from their grip on the world.
And so, when the Hunger is on him, he goes to the nearest city and seeks those who prey on their fellow men. There the hunters become the prey, as they give up their lives to fill his black, ragingly empty aura. On one such foray, he met another, a kindred spirit in a way: the Shadow.
The Shadow's blinding, throbbingly potent aura is usually hidden behind his thick mental shields, which is no doubt why he has never come to the attention of the Council. He has attained a raw, untutored mastery over it that even some of the Masters might envy - though none would envy the curse of his homozygosity, which makes him unable to turn the flow of power off.
Attracted to the Shadow's grim sense of purpose (and, it must be confessed, to the soothing power the man unconsciously radiates), and then later out of friendship and loyalty, the Forbidden stayed in Los Angeles longer than was really wise. (He did not burden his friend with the full knowledge of the Council, speaking only in general terms of his abilities and how he came by them.) Yet it turned out for the best in the end, for he met Rose.
Rose was what the Council calls a "natural" - someone with a blindingly bright aura, yet no training to shape it. She was like a life-battery, a sun shining in the night, and the attraction of opposites (positive and negative) spilled over into their emotions. The Forbidden could take life from her - nay, receive it freely offered - without fear of harming her. For the first time, he saw a way out of his cruel dilemma - a way to happiness and peace.
He stayed a little longer to help the Shadow rescue his son David and smash the evildoers who had kidnapped the boy. Then he bade the Shadow a fond farewell and went with Rose into the Sierra Nevada. What machinations the Council has sent after him, and how he has responded, are unknown.
But the Shadow's war goes on.
[Note that the character of the Forbidden is taken directly from a published short story, part of an award-winning anthology. But it's not plagiarism, because the character was created by the author of the story.

Brief plug: The story is "The Fix", in the anthology "The Lives of Ghosts and Other Stories" by Loren Cooper, my best friend. It won the Eppie for best e-book anthology of the year in 2001 (IIRC) and is available in paperback as well. It's on Amazon along with other books of his, if you're interested...]
[Bizarre thought that I just now had: Are the "Forbidden" and the "mindblind" one and the same thing? Recall that the Forbidden's mental powers, such as they are, stem from direct, almost physical manipulation of auras, not from conventional telepathy... In that case, the Forbidden's Mental Protection would be of merely Psionic origin.]