I admit my love for Wraith: the Oblivion perhaps prevents me from looking objectively at Orpheus, and accepting it on its own terms because I resist looking at the setting of the former through a different lens. I've ignored a great deal of the World of Darkness metaplot (namely, the Sixth Great Maelstrom) just to make Wraith games viable, as well as investing effort into updating the game to Revised rules (see Bylaws of Charon for this). So obviously, I like Wraith enough to not gut it in favor of the new game that would take up its banner.
However, this doesn't prevent me from seeing the value of Orpheus, at least those parts of it applicable to Wraith games. As I read through the Orpheus corebook, I saw some interesting ideas, my favorite among them being how Spite grants characters Stains, Vitality, and the way Nature was more tied into the character. Here, I'll explore various ways to retrofit some Orpheus rules and concepts into Wraith games. Note that this material is intentionally Wraith-centric, and presents Orpheus concepts through a Wraith lens rather than the reverse. (Turnabout is fair play, after all -- Orpheus plundered elements of Wraith for its own ends, so it's only fair that a Wraith loyalist would do the same in turn.)
However, you'll need a copy of the Orpheus corebook to make use of many of these rules; I could reprint the rules that I refer to, but I'm not so foolish to flaunt copyright law in such a manner and I only have so much time to write this stuff.

Body and Soul
Corpus, Pathos and Willpower: I have to admit I like the way Vitality is done for ghosts in the Orpheus setting. The developers have merged Corpus and Pathos into a single stat, which makes a certain amount of sense. Emotion isn't just important to wraiths -- wraiths are entities of emotion. A wraith that has suffered permanent corpus loss will have a lower maximum Pathos threshold, such scars are more than just permanent wounds, but reflective of a crippled soul. So while this means corpus and Pathos are still distinct (and thus, a systems-wide revision isn't needed to merge them), they're related more closely.
In short, the maximum Pathos for a Restless can't exceed her permanent corpus levels. These both are equal to 10 at character creation, but things that cause permanent corpus loss (such as Harrowings) will lower this. Also, permanent Willpower may not exceed permanent corpus, and if permanent corpus drops below permanent Willpower, those points in excess of corpus are lost forever. So if a ghost manages to lose two permanent corpus levels over the course of a chronicle, her maximum Pathos and permanent Willpower will be 8 each.
Recovering Permanent Corpus: Can a wraith "heal" permanent corpus damage? Possibly, yes, though it's not easy at all; otherwise, the concept of permanent loss doesn't hold much stigma, does it? Flooding one's corpus with Pathos, plus an exertion of will and personal reserves, allows recovery of such drastic wounds.
In gamespeak, the wraith must be fully healed, and expend a number of Pathos equal to twice her maximum corpus levels over the course of an hour. In addition, a number of experience points equal to three times her maximum corpus must be spent as well. Fulfilling these requirements restores one lost level. This corpus level starts out "empty"; it must be healed as a level of aggravated damage, though this may be done at the character's convenience.
Buying Corpus: If he doesn't mind a boost in power levels for experienced characters, a Storyteller may allow wraith characters to buy extra corpus levels, going beyond ten. Use the systems above for healing corpus damage. This option is expensive, and not easily attainable if the Storyteller is conservative when handing out experience points and opportunities for regaining Pathos. However, this doesn't allow ghosts to have Willpower ratings above 10.
One side effect of having corpus ratings above 10 is that the wraith will stand out like a beacon in the Shadowlands, being so full of life energy and passion. While this might be a good thing in some cases, such as when a Heretic is trying to convince a potential convert of his "path to life", it can (and does) draw unwanted attention from those who would snuff that light out. If you have the Wraith Players Guide, treat this phenomenon as the Corporeal Merit: Full of Life listed in that book (pg. 22).
Lower Starting Corpus: One option some Storytellers may wish to explore is starting beginning wraiths out with lower maximum corpus levels, similar to what Orpheus does with Vitality. Maximum corpus is equal to 10 minus [permanent Angst], representing the wearing away of identity and life energy by Oblivion.
Be warned, lower corpus will result in a lower-powered game, making wraiths easier to take down in combat, and (if the Storyteller uses the option) reducing the potential Pathos reserves available to those characters. While few people play Wraith do so because they like powergaming, in my experience, such a drastic reduction in power could discourage players, as they feel Restless characters have quite enough going against them as it is. Storytellers may wish to boost wraiths in other areas to make up for this loss, such as allowing the purchase of corpus levels with freebie points (I recommend four freebie per level). Being able to buy corpus levels in-game, as described above, would also be a good idea.

The Dark Side
Angst and Identity: I rather like the way Spite and Vitality interact, wherein spooks lose identity and become more destructive as Spite climbs over Vitality (as outlined on page 193 under Spite Ascendant). In Wraith games, Willpower = Vitality, while Angst = Spite. Use temporary or permanent Angst, whichever is higher at the time, and compare it to Willpower to determine the wraith's behavior.
Having temporary Angst affect a wraith's behavior might seem a bit harsh, but it reflects how the waxing nature of a character's internal darkness slowly corrodes his identity. This may lead to devil's bargains with the Shadow, where a desperate Restless slowly being taken over by his Shadow -- and without access to a Pardoner -- may actually choose to cap out his temporary Angst and gain a permanent dot, if the new Angst rating will be lower than the temporary points he has. Also, this option gives Restless characters a little more leeway, where a higher Angst than Willpower doesn't necessarily mean Spectredom for a wraith... though this line should not be pushed.
Angst and Stains: Spite is a clear parallel to Angst, and as such, it seems intuitive that Angst might grant similar left-handed benefits to Restless. This would be a revision of sorts of the Angst rules, where giving into one's dark urges grants the character extra power... but at a price. This might lead to certain wraiths cultivating their Shadows for power, rather than fighting them as adamantly as they should.
I feel this reflects the nature and theme of Wraith better than the standard Wraith rules, in fact, which gives characters no benefit from Angst. Granting Stains for Angst increases more internal conflict for characters, who now have to wrestle with maintaining a balancing act with Angst, either denying it as best one can and sacrificing the power it grants, or allowing it to blossom in order to reap its benefits (and such highly personal conflict is always a good thing for Storyteller games, Wraith especially).
For every two dots of permanent (not temporary) Angst a character has, he gains one Stain. Stains are usually unnoticeable, and are dormant until the ghost chooses to activate them (however, this may not hold true for those with especially high Angst, who display some of their stains openly on the corpus; see below). Manifesting a Stain grants the character a point of temporary Angst, and the Stain may be maintained for a number of turns equal to the character's permanent Angst rating; accruing more temporary Angst will allow the Stain to be retained longer.
Permanent Stains: When permanent Angst reaches 5, and for every point by which permanent Angst exceeds Willpower, the character can manifest one Stain for free, gaining no Angst for its use. In fact, such stains remain manifested constantly, and the character can't hide them; his Angst is so strong that it mutates his corpus, bearing his corruption for all to see. Some permanent stains can be Moliated away (and their benefits lost), but always return after a scene. While a social stigma among wraiths, Spectres and other Oblivion-serving beings are drawn to those who are warped so by their Shadows; for every permanent Stain the character has, increase social roll difficulties by 1 among wraiths, and lower such difficulties by an equal amount among Spectres and similar creature.

Stains Here is a brief list of sample Stains that a wraith might manifest. Some are inspired by the stains in Orpheus, others are my own creation. Feel free to adapt more Stains from the Orpheus books, or come up with more of your own. Note the effects of these stains wax with permanent Angst, growing stronger and more fearsome as the character's soul becomes darker. A ghost can't choose to "tone down" the benefits of a Stain for a less nasty effect; such is the price of a high Angst. Note that Stains are manifestations of the soul, and affect the corpus. Thus, wraiths Skinriding mortals and Risen don't manifest Stains. However, a Restless with Embody can manifest stains normally, as the ghost is inhabiting solidified corpus. ♦ Claws/Teeth: The ghost has long, wicked claws on his hands, or sharp teeth reminiscent of a shark or wolf, which grow larger and more sinister as Angst accumulates. They inflict Strength in aggravated damage; at Angst 4, 7 and 9, the damage done increases by one die. However, either speech or manual manipulation (depending on the way the Stain manifests) become progressively harder, imposing a +1 difficulty penalty to related rolls for every extra damage die done by the natural weapon -- claws would inhibit use of items (including weapons), while Expression and Performance: Singing will be difficult for those with a maw of razor-sharp fangs. ♦ Corrupting Touch: The very energies of Oblivion seep from the wraith's body, inflicting damage upon whomever and whatever he comes into contact with. At first this is a subtle effect, but as Angst increases, black tendrils of Oblivion (or in some cases, acidic plasm) can be seen dripping from the character's corpus. When he touches another wraith or an object, or when an object or wraith contacts her, one die of lethal damage is inflicted on it. (Storytellers may assign soak pools or health levels for especially resilient items, like weapons or walls, but small and less durable ones simply crumble to dust) At Angst 4, 7 and 9, the damage done increases by one die. The drawbacks of this Stain are obvious; friendly contact and personal possessions are right out. The character also suffers lethal damage in any scene he uses this Strain equal to half his damage pool for the effect (round up), which may be soaked at a difficulty equal to the character's Angst (damage isn't cumulative for multiple uses, however); such contact with the forces of supernatural entropy takes its toll on the user. ♦ Dark Lore: Preferred by those Restless with an intellectual nature, this Stain temporarily imbues the character with knowledge and wisdom she didn't have before for a scene. The Shadow pulls the desired knowledge from the tattered and wounded remnants of memories and thoughts that float through the Tempest, as well as from the whispers of Spectres and other horrors, cobbles it together, and injects it straight into the Psyche. While the information may well be useful, its schizoid nature warps the mind of the would-be-scholar, leaving her mentally spent and possibly traumatized. Use of this Stain grants two dots in any Knowledge Ability the character desires; an additional dot is gained at Angst 4, 7 and 9. These dots aren't cumulative with any existing Knowledge dots, but a higher Dark Lore rating will replace the normal, lower rating for the scene's duration. The character must then exceed the number of dots gained through Dark Lore with successes on a Willpower roll; any Knowledge dots in excess of Willpower successes drains a point of temporary Willpower from the wraith. If at least one Willpower success isn't rolled, if the ghost's temporary Willpower is reduced to zero, or if the roll botches, the character gains a temporary Derangement. If Dark Lore becomes a permanent Stain, the player must specify the Knowledge this Stain grants. Thereafter, she has those Ability dots permanently, but suffers a permanent Derangement also (though she need not make Willpower rolls to avoid further derangements when accessing the Dark Lore). However, this Knowledge is set and can't be "switched out" for another. ♦ Enhanced Arcanoi: A popular choice, though one with a higher cost than most wraiths expect, this Stain actually augments the effects of the character's arts by tapping the Shadow for power. Low levels of Angst add a die to rolls involving arts for the duration of the power, though at ratings 4, 7 and 9, another die is added to Arcanoi rolls. However, the Shadow's influence often corrupts the effects of the art, creating unexpected and malign side-effects. For example, using Charitable Trust (Usury ●●) might inflict Angst on the recipent as the ghost heals her, while Puppetry arts may inflict damage on the mortal possessed. To avoid such nasty side effects, the wraith must make a Willpower roll and gain a number of successes in excess of the Stain dice added to the art effect. (Note that the wraith can't scale down the effect for an easier roll.) ♦ Hulking Size: The ghost's corpus swells with unholy energies, investing it with great strength and resilience. The form taken looks like a huge, ugly, distorted version of the wraith; as Angst builds, the form gets larger and more grotesque, often sporting swollen musculature, deformed bones and asymmetrical limbs. This Stain grants +1 Strength. At Angst 4, 7 and 9, the Strength bonus increases by one, and an additional corpus level is gained; however, each Social Attribute loses a dot for every bonus corpus level gained. (Damage inflicted on the wraith goes though these extra corpus levels first; any corpus levels left over at the end of the scene or when the effect ends are lost.) In addition, the character gains a penalty in another Attribute equal to the number of bonus corpus levels, chosen by the player (once the Attribute is chosen, though, the penalty always applies to that Attribute). The character can be a mindless berserker (low Intelligence), a lumbering, plodding giant (low Dexterity), is unable to think quickly (low Wits), or become insensate with hatred (low Perception). ♦ Tentacles: The wraith sprouts eight foot-long tentacles from his sides, shoulders or elsewhere on her body, which are useful for holding items, grabbing foes and other such tasks. At first the character only has two, but at Angst 4 and 8 the character spouts another pair. The Strength of the tentacles is equal to the character's Angst, and the character uses Dexterity + Brawl to attack with them. They aren't effective weapons when used to hit (inflicting only half their Strength ratings in bashing damage), but ideal for grappling; the tentacles' full Strength is applied to restraining foes (inflicting their Strength in bashing damage every turn) and maintaining holds. However, the tentacles have a mind of their own (or rather, the mind of the character's Shadow), and are prone to acting against the character's wishes at time, such grabbing onto allies, flailing dangerously or even causing damage to the wraith herself. When the Shadow tries to assert control over these limbs, the wraith's player must make an opposed roll of Willpower verses Angst to reign in his tentacles. ♦ Tough Corpus: The Restless' corpus becomes unnaturally resilient, granting a +1 bonus to soak rolls. At Angst 4, 7 and 9, the soak bonus increases by one die. The Stain may manifest as scales, the armored carapace of an insect, layers of fat and muscle, or elephantine skin. As with all Stains, along with the good comes the bad: Tough Corpus effectively destroys the character's tactile sensation, and reduces his Appearance by one dot per die of soak bonus.

Projectors
The emphasis of Wraith games is, and should be, wraiths. However, this doesn't necessarily preclude the existence of projectors as Storyteller characters that encounter ghosts in the Shadowlands. Projector groups (crucibles) that include wraith members, are possible for chronicles for a change of pace. As we're defining projectors through the Wraith system, and as projectors visit the Shadowlands while separated from their bodies (rather than invisibly travel through the Skinlands), this necessitates some changes to the systems for projector characters.
Types of Projectors: There are two types of projectors, Skimmers and Sleepers, defined by the means they separate their souls from their bodies to enter the Shadowlands.

♦ Skimmers: These projectors have mastered the ability to separate their spirits from their bodies naturally, usually through rituals that allow characters to enter the lands of the dead, such as the Descent of Orpheus or the Ekstasis. Some psychics have developed Psychic Numina similar to Astral Projection that allows entry into the Underworld. Another method includes use of Mind and Spirit Sphere magics, though it's often easier and less risky for Willworkers to simply breach the Shroud and enter the Shadowlands bodily. Such characters must enter the Underworld under their own power, but don't rely on technological crutches to get there.
Skimmers are highly individualistic, as any given one has her own reasons for going to the Shadowlands. Some may wish to contact dead relatives, others may gather information among the Restless, and still others are researchers of the paranormal who want hands-on experience. However, some -- such as the Benandanti -- are ghost hunters, driven by holy zeal to free wraiths from the Shadowlands so they may meet their fates (whether the ghost in question wants to be "freed" or not), while other Skimmers hunt Spectres or other dangerous spirits.
♦ Sleepers: Like skimmers, Sleepers' souls leave their bodies and enter the Shadowlands. However, rarely do such characters do so under their own power; they rely on technology. They are placed into a chamber or capsule, hooked up to biofeedback machines and other monitors. Next, they're injected with drugs that serve three functions: it places the character into a deep coma-like sleep, "loosens" the connection between the Quick's spirit and body, and allows projection into the Shadowlands.
Most Sleepers are just that: Unenlightened proles sent into the Shadowlands at the behest of higher-ups, Technocrats that are most often Void Engineers or Syndicate operatives. These projectors are the most likely to be hostile to wraiths, as they're usually sent by their patrons to "neutralize and contain aberrant psychic manifestations". However, there are other, "rogue" Sleepers, either Sons of Ether or their hapless subjects, which have their own motives for entering the Shadowlands and are usually not so inimical to ghosts.
Game Rules: While separated from their bodies, projectors are essentially watered-down wraiths. They can travel through the Underworld, communicate and physically contact ghosts, become intangible and walk through walls, and perform other actions that ghosts can. Arcanoi and other powers that affect wraiths affect projectors as well, with some exceptions (see below). While in the Shadowlands, characters aren't subject to the Fog.
♦ Health: Projectors have only seven corpus levels while projecting, but their spirit-bodies don't suffer wound penalties from damage until they return to their bodies. They take damage as ghosts do while projected, including reduced damage from bashing attacks (see Bylaws of Charon), though while not projected they follow the rules for mortals. Damage taken while projecting transfers one-for-one to health level damage, though no injuries will be evident on the physical body once the soul is returned; the wounds aren't physical in nature, but no less real or deadly, and they suffer penalties for health levels lost as corpus in the Shadowlands.
♦ Powers: Mortals can't learn Arcanoi, which are secrets restricted to the dead, no matter how much time they spend projecting. However, certain Numina, particularly Psychic Numina, are available to projectors (assuming of course they have them, as a Sleeper being sent into the Shadowlands won't magically gain powers). It's possible for projectors to use special items able to exist in the Shadowlands; these may be either enchanted relics, or hypertech created by technomages).