Passive
Aging: Wolfram doesn’t age. He can, in theory, live forever, but the older a vampire is the less they seem able to keep up their human appearance. Vampires like the Master or Kakistos, for example, appear to be permanently stuck in their demon forms. Age also affects a vampire’s strength, stamina, agility, and reflexes, making them increase yet more as the decades pass. Being that Wolfram is over 270 years old, he’s an incredibly formidable man.
Body Heat: The shows have displayed vampires as having the potential as coming across as colder to the touch than normal people, but it’s also true that most that have come into contact with them seemed not to have noticed. When one vampire, Spike, was read with a thermal scanner, he was shown to be at 62.3 degrees Fahrenheit. This could just be because he was currently standing still, however, and vampires may be able to generate a warmer temperature. Yet, it’s also been said by Wolfram himself that he doesn’t have body heat, so what temperature they do have could just be based on the amount of blood in their system. It’s enough of a murky point that, unless there’s an issue with it, I have Wolfram feeling cold when he’s been still and lukewarm when he’s been in motion. If he isn’t feeding, he’d feel cold no matter what, getting that much worse the more time he goes without.
Breathing: Wolfram, as he doesn’t breathe, cannot be affected by a lack of oxygen (i.e. drowning) or poisoned using any kind of airborne agent. He still possesses the reflex, however, and can made to feel like he’s choking and do shallow things that require breathing like talking or smoking.
Detective: Wolfram has a very acute understanding of behavior that, as Angelus, made him an effective monster and emotional manipulator and, as Angel, a skilled detective.
Disease Immunity: Like the title says, Wolfram is immune to any kind of disease.
Endurance: Wolfram has been shown capable of getting cut and shot without being overcome by the pain, but other instances (such as when he’s gotten dramatically impaled) have shown that it’s still possible. It’s because of his endurance that he’s also able to take good slugs from super strong monster fists (of DOOM) without flying back thirty feet - if he’s on his guard. This also allows him to jump from or fall from heights that would shatter every bone in most peoples’ bodies and survive.
Food and Drink: Normal food and drink tastes fairly bland to Wolfram, but he’s able to consume them just the same. Don’t ask me where it goes.
Healing: Wolfram, like all vampires, heals very rapidly. Yet, it’s not instantaneous as he’s often being patched up by friends after being wounded in fights (likely for the sake of reducing irritation rather than fighting off infection). Wolfram has been noted to have well above average healing, however, even for vampires. Spike is similar, which makes this a factor I would attribute to age.
Human Blood Flow: Despite lacking a beating heart, Wolfram's blood still moves around via some unknown mystical aspect of his physiology. This means he can be knocked unconscious when this flow is interrupted to his brain. This also allows him to get drunk and be affected by certain poisons or drugs, but it takes more than the average dose to get past his vampiric constitution.
Pain, Pressure and Tears: Wolfram has the same capacity for pain as mortals (though they are better able to handle it) and Wolfram has shown on multiple occasions that he is capable of generating normal tears. Wolfram also proved that, when he was sunk into the ocean to infiltrate a submarine, he was immune to the deep pressures of the ocean.
Photographic Memory: Wolfram has a perfectly photographic memory.
Reflection: Wolfram lacks a reflection in any kind of reflective surface, be it water, or mirrors, etc. He can, however, still be photographed and caught on video tape.
Sanguine Appetite: Wolfram requires the blood of any mammalian creature to maintain his sanity and his strength. This can be humans (the most fulfilling and the most delicious), otters, cows, etc. This doesn’t need to be freshly from the body and can be consumed from a blood bag, cold, or even heated up in a microwave oven. Wolfram doesn’t need blood to survive, however, and could theoretically live forever without a drop of the stuff. Going without blood first reduces his strength and makes him able to feel the cold while becoming notably paler. Longer starvations result in damage to higher brain functions, inducing things like hallucinations, and at this point only the blood of a live human can recuperate him. Lastly, at his worst stage, he would become a living skeleton. If he feeds off someone under the influence of something, he would be easily affected by it as well. In addition, if the person that Wolfram is feeding off of has particularly powerful blood (a half-god, a supernatural warrior, etc.), his own power will greatly increase for a mild duration afterwards.
Senses: Wolfram has greatly enhanced senses of hearing and smell along with a certain degree of night vision. A good example of his sniffer would be the scene where he proves his olfactory prowess to Wesley by telling him he had sex with a bleached blonde the night before. He’s particularly sensitive to the presence and differing smells of blood.
Sire’s Connection: Wolfram has shown that he retains a psychic connection to those he sires, able to have dreams about their activities and sense them when they’re near.
Special Life Force: Beings that feed directly off of a person’s life force have been shown to die when doing this on Wolfram. His brain will also fail to give anything sustenance if consumed and telepathy fails outright when attempted on him.
Temperature Toleration: Temperatures both high and low (save the obvious extremes like fire and being frozen with liquid nitrogen, etc.) don’t affect Wolfram and won’t cause him any real discomfort.
Vampire Sense: Wolfram can sense when someone is a fellow vampire.
Active
Artist: Wolfram has shown himself to be a very talented artist. Perhaps factoring into it, he also has rather nice handwriting (which, when he revealed this to his son, had him met with the comment ‘You girl.’).
Demon Form: When not hiding behind his human visage, Wolfram looks as all vampires do. This ‘demon form’ affects only his face in the way of brow ridges, golden eyes, elongated upper canines, and pointed upper incisors. This form is brought about before feeding if done directly from the vessel, but can also be compelled to the surface if Wolfram is in the middle of a stressful situation (like combat), when he’s angry, or when he’s suddenly or unexpectedly injured. He can also, as implied via the feeding note, ‘vamp out’ at will. There’s a slight change in his vocal cords, too, that resembles a lion or a tiger when he growls. Taking into consideration the Pylea episode where he has to vamp out to defeat the Groosalugg, it also implies that doing so increases his strength and his speed that much more, if only by a moderate amount. Wolfram speaks normally in this form, but growls and snarls sound much more like a tiger or a lion than anything close to human vocal cords.
Martial Arts: Although, to my knowledge, no particular style has ever been mentioned, Wolfram has had over two hundred and forty years to practice his combat skills and has shown himself to be incredibly skilled in a wide variety of different martial arts styles. These have helped him go up against powerful demons and face hordes of enemies and come out victorious.
Stealth: As a predator, Wolfram has had a long time to develop the quieter aspects of the hunt. Through his course in both shows, he has displayed a prowess at applying this to situations like stalking someone or simply tailing an individual with a great amount of silence and aptitude.
Superhuman Speed: Like all vamps, Wolfram possesses superhuman speed. As with his strength, he has this at higher levels than a lot of his kind and has shown himself capable of crossing rooms in the blink of an eye.
Superhuman Strength: All vampires have superhuman strength, but it seems to vary based on their age. Wolfram has been shown to have strength at much higher levels than the average vampire, likely due to this very fact.
Torture Expert: Given his past as Angelus, Wolfram has shown a masterful efficiency in the ‘art’ of torture.
Weapon Proficiency: Wolfram has displayed a great skill with a wide variety of different medieval pieces of weaponry. Though he has had just as much time to refine this as his martial arts, he's always shown himself to be more of a pugilist than a blade-wielder.
Weaknesses and Vulnerabilities
Fire: While normal vampires that have been set on fire are turned to ash almost instantly, older vampires like Wolfram take more time. This, however, is still a potential way for him to go out.
Cross: While simply holding two things together to form a cross won’t do anything, holding up a normal cross in front of Wolfram can cause him to recoil in instinctual fear. He has shown, however, that he’s able to maintain his calm in the face of them as well. It depends solely on the situation. If touched by one, however, his flesh would smoke and burn.
Decapitation: If Wolfram is decapitated, he and his clothes will turn to dust and he’ll die instantly.
Garlic: Although garlic has been confirmed on the show to affect vampires, what it does exactly has never been revealed. I simply assume their heightened sense of smell can’t stand it, but that it’s no more affective than bad body odor.
Holy: Holy water can badly burn Wolfram and, if ingested, will kill him. Recently consecrated ground and Bibles also burn him if he touches either.
Invitation: If used as a place of residence for anyone, Wolfram cannot enter a building without getting some form of invitation. It can even be written, but it has to be given in some form just the same. If not, Wolfram would find himself running into an invisible barrier that would only go down once all the residents were killed. If the residence belongs to a demon, he can come and go as he pleases. These rules only apply to private residences, as any kind of temporary housing (hotels, the temporary housing in Edensphere, etc.) is unprotected. If someone invites him in, they have to be a resident, the owner, or an acknowledged guest. Once invited in Wolfram will no longer need an invitation unless a special ritual is performed.
Perfect Happiness: If Wolfram ever experiences a moment of perfect happiness, one where he doesn’t feel any of his usually overwhelming guilt, he’ll lose his soul and become Angelus again. This can be induced synthetically, via happy pills, but his reversion to Angelus then is only temporary.
Sunlight: Although the canon 'rules' for sunlight are different, in regard to Edensphere, when about in partially sunny days, Wolfram will feel a general sickness and discomfort. Cloudy days will still be uncomfortable, but they'll be more tolerable. Brightly sunny days, however, will actually cause Wolfram to blister.
Wood: If any kind of wood goes through Wolfram’s heart, he’d immediately turn to dust and die.
Unlockable
Knowledge: Wolfram’s age has made him very knowledgeable on the subjects of history and demonology. I planned on having him remember bits as they become pertinent, or even just randomly, but never direct moments involving them in his own life unless unlocked via a memory.
Linguist: Over his many years of existence, Wolfram has learned several languages. These include English, French, German, Greek, Italian, Korean, Latin, Romanian, Russian, Spanish, and Tibetan.