Sabrina is a 20th-century English pagan from the West of England. Sabrina it is an adventuring pseudonym: she was born near the River Severn (Sabrina in Latin). In Qwanet, Sabrina is known as "Sabrina Neplosembais" (the adjectival nickname is not complementary, so I won't translate it).
Exactly how a 20th-century Englishwoman comes to be in a fantasy campaign is entirely up to you. The important point is that everyone everywhere else in the universe is thankful that she is somewhere else. How she comes to be half-elven is equally unimportant - perhaps both of her parents, although human, had a small amount of elven ancestry, and she inherited enough from both to be half-elven.
Sabrina could be considered pretty, even beautiful, by anyone who has seen her. But anyone who has heard her would not wish to repeat the experience. She talks loudly and incessantly about anything that comes into her head. Who else would talk about the weather when she is ten levels underground?
Sabrina, although highly intelligent, has no particular ear for languages. She speaks the Common Tongue reasonably well, but ungrammatically and with an accent which causes native Atlanteans to wince. She has no ear for music either, and her singing voice is horrible. This does not stop her inflicting it on people.
Sabrina believes she knows what is right, not only for herself, but for others, and she will not hesitate about imparting this information. If you should clean all that monster blood off your sword before it rusts, Sabrina will tell you so. Several times, with increasingly sarcastic comments added to emphasise the point. If she thinks you should learn a new skill, she will not only tell you so, but inform you of several places where you could go to learn it.
The really irritating thing about Sabrina is that she is usually right. You do not want to open that particular door, because there really is, as Sabrina says, a monster hiding behind it. You should mend your boots, because there will be something nasty underfoot on the next level. You should have prepared magic missile rather than sleep, because this particular level is full of undead and your sleep spell is useless.
As if this were not bad enough, Sabrina is also fond of practical jokes. Her current favourite is a first-level spell which changes the colour of things. If you see someone with a pink longsword or a sky-blue holy symbol, it is likely that Sabrina has been in the area in the past week.
Sabrina's charisma is high, partly because she is physically attractive and partly because she finds it easy to persuade people to do what she wants. After listening to her for a few hours, they prefer to agree to what she says rather than endure any more.
Sabrina is also obsessive. She believes that it is her religious duty to be good at everything. What this means in practice is that she spreads her talent too thinly. Although she is competent at almost everything, she is not outstandingly good at anything.
[AD&D-Specific:] Sabrina, half-elf female, Str 14 (Stamina 16, Muscle 12), Dex 17 Con 16 Int 17 Wis 16 Cha 16 Align NG Hp 74. Height: 5'9", weight 136 lb. Age: Early thirties. Ranger, level 10. Mythos Priestess, level 13. Transmuter, level 12. Psionicist, level 12.
Sabrina stretches the rules almost to breaking-point, but not quite. Ranger-druids, multiclassed half-elven transmuters, and multi-classed half-elven psionicists can all be found in the rules if you look hard enough, and half-elven druids with 16 wisdom and 16 charisma can reach 13th level if they defeat the local 13th level druid in an appropriate contest. Perhaps she talked him into submission.
Sabrina's warrior skills are those of an athlete, specialising in cross-country running and field sports. But a scimitar is just a hockey stick with sharper edges, isn't it? Sabrina's ranger skills are those which could reasonably be learnt in a posh girls' school on Earth (pick pockets, for example, but not tracking). Sabrina does not wear metal armour. This is partly so that she can use her magical and mental powers, but also partly because she looks really sultry in black leather.
The Complete Ranger's Handbook suggests that Militant Ecologist would be an interesting kit for a ranger, and Sabrina fits this ideal well. On her homeworld, she would be considered a Forest Runner. Her nemesis has followed her from Earth: Bardolph Littlejohn.
Sabrina's species enemy is lawyers. According to Sabrina, lawyers are undead, and should be destroyed on sight. Destroying them is not the same as killing living beings. This unusual viewpoint does not get Sabrina into trouble often: for example, the legal system in Atlantis in inquisitorial, while that in Megalopolis is based on trial by combat; there are no lawyers practising in either city.
Be warned that Sabrina recently reached 10th level as a ranger, and her followers should start showing up during the course of the campaign. These followers will ignore any verbal abuse Sabrina sends in their direction; anyone bothered by such things would not have become one of her followers in the first place.
Unless you have a specific mythos planned out into which Sabrina would fit, assume that her religion is the neutral good religion practised by swanmays and druid followers of player-character rangers. It is more or less druidic, but she has the additional benefit of regenerating 1hp per turn. She does not kill except for food or in self-defence, and she does not treat living beings as inanimate things (so will not, for example, ride on horseback), but apart from that, almost anything goes.
Sabrina believes that her religion is that practised by Britons in the days of the Roman Empire. To get a feel for this, see the Online Temple of Sulis Minerva. The facts do not support this belief, but she will nag into submission anyone who holds a contrary opinion.
As a transmuter, Sabrina is a member of the Learned Society of Alteration and Alchemy. The majority of the spells in her spell-book are those which a commercial spellcaster might cast, rather than those which are of particular use to adventuring spellcasters. When adventuring, she favours burning hands and its variants.
Sabrina visits Atlantis reasonably regularly to keep up-to-date with the latest spell research. This includes a memory spell which allows her to use a corner of her mind as a portable spell-book. She can re-prepare any of fifteen 1st-level spells, any of six 2nd-level spells, the 3rd-level spell fireball, and the 6th-level spell flame arc, just by resting and meditating, without any need to consult her spell-books.
As a psionicist, Sabrina's primary discipline is telepathy. It is far from unknown for her to use post-hypnotic suggestion in the course of her practical jokes. PSP 97.
As a half-elf, Sabrina has these abilities: less sleep, resistance and stealth. It surprises most people to discover that when she is on her own she can keep quiet.
The restriction that she may not own more treasure than she can carry is not a problem for Sabrina. Everything she owns, other than that she normally carries with her on adventures, is stored in her locker in the Learned Society of Alteration and Alchemy in Atlantis. This includes her spell-books and rather a lot of sapphire jewellery. Sabrina likes sapphires of all colours (remember that not all sapphires are blue) and sometimes acts less than rationally when sapphires are on offer.
Sabrina routinely gets, and deals with, hassle from priests and followers of Ares and Poseidon. As a result of this, she rises in level rapidly despite having to divide her experience points four ways.
Sabrina is a very close friend of Aurelius, Vladimir and Dalinda.
Sabrina is usually on good terms with Pamina.
Sabrina detests and despises Sir Digby de Breosy, and will do her best to kill him should they come anywhere near one another. She holds him personally responsible for the murders of nine million women who shared her religion.
Sabrina, being who she is, has to go one better than other rangers and have two nemeses. One of the things which keeps Sabrina alive is that Sir Digby de Breosy and Bardolph Littlejohn, hate one another almost as much as they hate her.
In case you were wondering, yes, this is the Sabrina who stars in my guide to Basic Sentence Patterns in Japanese. The scenario actually took place not in Atlantis but in the headquarters of the Four Yellow Circles Gang of Qwanet. I just thought it would be easier to transliterate Atlantis into katakana. She went to Qwanet to improve her sneaking-about skills (hide in shadows, move silently and sneak attack) in urban settings.
Note for DMs:
Sabrina's main function in a campaign is her entertainment value. That's entertainment for DMs, not for players.
Additionally, Sabrina can be used to provide player characters with hints about what they are doing wrong. Wipe the mud off your boots before you try sneaking around indoors using a ring of invisibility, stupid!
If the player characters need a guide around Atlantis who will ensure that they do not get into serious trouble, Sabrina, as an adventurer who often visits that city, is a natural choice.
If the player characters come up with a really amusing practical joke that they want to play on someone, Sabrina will be only too happy to provide any necessary transmutation spells or telepathic psionic contributions. She might, of course, add to the fun by using them on the player characters as well.
As noted above, Sabrina's followers should start showing up during the course of the campaign. If you need to fill out a party and the player characters are on good terms with Sabrina, she will lend them the use of some of her followers. It will do them good to go adventuring and gain experience.