Seth Gebsen is the seventh son of a seventh son, and that was enough to give him what's often called Second Sight.
He's always been able to see through the "smoke and shadows" that muddles the reality of things, and he first showed that power at age five when he innocently asked his Mother why the man had red skin and how he got his tail to move around like that.
The man in question was an old boyfriend of his mother who had returned and was apparently trying to rekindle their former relationship while Father was busy with his "Men's Club" - but the club was actually a society of magical wardens who fought the Dark Forces, and Gregory Gebsen was one of their most effective agents.
Elizabeth Fairweather Gebsen was not a helpless woman. She was fully aware of the warden society and her husband's absences were not resented. She realized that the old boyfriend was, or had been replaced by, an Incubus, and she engaged in magical and physical combat, driving the Incubus into a demon-trap and holding him there until her husband arrived.
Unfortunately, her son had left the sight of his Nanny for a mere second, and that was long enough for them to replace him with an imp, and that gave them time enough to take Seth quite far away before the substitution was discovered. They interrogated the imp and it knew nothing, but spells of divination said that he was still on Earth but not in the Mortal Realms. They slowly narrowed down which Otherworld he'd been taken to, and then had to negotiate to get him back.
When they found the place he had been taken, they learned that their son had been subjected to the Sombranjonix Desecration, a ritual curse from the Atlantean war that was supposed to enslave him to a spirit of evil and destruction. As far as their own magic could tell, the "evil" part wasn't there, and the "destruction" was questionable and "enslave" was nowhere near the right word for the actual situation.
The curse had taken Seth and a child the same age from another Otherworld and fused them into a single being. The parents of that child had recovered their chimerized offspring and he was safe, but in their home, and they wouldn't release him to strangers. The situation was complex as the Otherworlders had also been wronged, and as a side effect of the actions of Gregory and Elizabeth's enemy, and the use of an ancient spell that the Otherworlders found utterly horrible (even more than humans did) led them to request, through diplomatic channels, that an Arbiter be set to help them determine who would have custody.
The Arbiter asked each, independently, whether they would consider the child entirely theirs, or only half theirs. The Otherworlders said the latter, holding no interest in the human part, but the Gebsens were willing to accept both. The Arbiter declared the judgement: since the Gebsens claimed both halves, and the Otherworlders only half, the human half was undisputedly the ward of the Gebsens, but the other half would be granted evenly to both sides. That made the Gebsens 3/4 custodial, and the Otherworlders 1/4 custodial. Thus he would spend a quarter of the year in the Otherworld and the rest in the Mortal Realm.
It was two years before Seth was finally returned from the Otherworld. When he did, he was rather changed.
First, he was a snake from the waist down and scaled overall; he also had four arms so parity-of-limbs was kept.
Second, he needed to be at least partly in shadows for several hours a day or get sick.
Third, along with Second Sight he now had the power to shape shadows.
Amazingly, he was still sane, still himself, almost indistinguishable in personality and demeanor except for two years of growth and maturity from when he was taken. He recognized that he had four parents, not two. He sometimes referred to himself as "we" but mostly to tease his parents.
And then came the problem of how he could go to school, since he was at least half-snake, and illusion magic could only cover his appearance, not the reality of his half-serpent body. On top of that (in accordance with the Arbiter's ruling) he would return to the Otherworld to a place called the Shadow Courts, vanishing the last week of November and reappear the first week of March, and that put him out of synch with the school system, even with private schools.
The society of wardens shifted Gregory's assignment to a remote area, setting him up in one of their isolated houses in a remote place where they could live away from other people, and Seth could slither about the grounds outside as much as he wanted. Some of the other wardens were pressed into the job of tutor when they weren't away, and Elizabeth, having left her "day job" as a combat trainer, began training him in the proper use of sword and gun, partly because he was bored by lack of physical activity, and partly because she was bored by having nothing else to do that challenged her. He was, like most serpents, extremely strong. Note, he was taught Canadian French and the Moroccan dialect of Spanish by wardens for whom those were native language, and he kept up his studies as he got older.
At age 9 his father began training him in combat magics that did not rely on him tapping shadows. With shadows he was a prodigy, but without them he was barely better than a novice human, even with his Second Sight showing him how the magic threads were woven. That was also when they noticed that he seemed older than he should be, and he admitted that he was spending a half-year of subjective time with his other family, because they hadn't understood the implication of the Arbiter's question - and that meant he was picking up an extra quarter-year every year. There was nothing to do about it; it wasn't unfair, so his parents began exchanging letters between them when he went either way.
Then, because his parents were still healthy adults, his sister Mali was born when he was ten - while he was away in the Shadow Courts. He came back to find a tiny human to cherish. She hated it when he had to vanish, and that seemed to change something in him. Perhaps it was being physically older than his age, perhaps that he knew someone depended on him more than he depended on them. He started to study his magic with much more focus, learning to hold non-shadow power longer and in more useful amounts. Sometime during this process, his Second Sight was locked down so that he wouldn't be made vulnerable to things that could use it to harm, requiring a spell to unlock it.
When he was fifteen, he returned from the Court walking on legs, and with the normal number of arms for a human, and without obvious scales, and told his parents that he wouldn't need to return there for so long any more. He'd achieved his majority there, though he still had to visit once or twice a year for birthdays and holidays, and they agreed to his leaving when it was necessary. (Not that they could really object.)
They returned to the city, and Seth went to an ordinary school for two years. It sucked. He had spent too much time on magic and the history of the Shadow Courts and not enough on mundane Terrestrial things, and he was two years behind where he should have been. He studied hard and caught up in many areas, but he's still arithmetically challenged (slow at calculation) and has odd gaps in history, current events, and culture. On the other hand he's a great drummer, and the two years in muggle schools did let him figure out how people interact.
On the upper other hand, his shadow powers were growing stronger and his time spent away from the Shadow Court meant he wasn't being trained as well as he had been. When he started accidentally making self-willed if temporary shadow-beasts, it was clear he needed to be better trained.
His sister had began public school and wasn't so dependent on him, and his parents decided that his last two years pre-collegium would need to be at a place where he could openly study not only his regular academics, but also how to manage his powers better. A place called "Coral Springs High."
Note: this differs slightly from my approved sheet because of timing with edits and pages being locked. The changes match what I discussed with Poseidon.
Shady Character
Shadows are not darkness. Shadows are what happens when light is occluded, with a perceptible demarcation between light and darkness. Seth is a half-shadow elementalist, a chimeric blend between a human and a serpent-being from a pseudo-elemental Otherworld. As a shadow elemental, he needs to be in his element: not just "dimness" but the sharp boundary between light and darkness, for at least three hours a day, preferably spread out like eating. Otherwise, he gets sick, like someone who hasn't been able to sleep AND has a vitamin deficiency
While he can use any kind of shadow that he can touch, Seth works best with sharp shadows, that is, the kind that are clearly demarcated. The weaker the difference in illumination the more effort to use it. His reach is improved by sharpness as well. He can be confounded by extremely bright light that prevents any shadow, or by being in complete darkness away from any source of light. It's the edge that's important.
When someone who is casting a shadow or in the shadow-realm within a mile or so of him says his name or talks about him, Seth will know it. He can focus on it and eavesdrop but it takes effort and he can't do anything else while that happens. Also, he can understand (though not necessarily respond in kind) when someone is talking TO him under those same conditions. This phenomenon used to freak him out when he was younger, but now it just sends chills up his spine.
Seventh Son of a Seventh Son
Seth and Sseth (his shadow-serpent counterpart) were both seventh sons of seventh sons, as well as being magical counterparts, unbeknownst to the demons who performed the ritual. This compatibility resulted in their complete fusion into a singular being. Seventh Sons are usually magically gifted, having Second Sight, the ability to see through glamourie and to see the threads of magic. Each compounding of generations grants a stronger degree; Seth has four compoundings (twice two) and as a result, had to be locked down, because his constant openness meant that complex or dangerous magic forces could get at him despite normal wards.
Patchy Education
Seth is bad at math. (He has dyscalclia, a disorder similar to dyslexia which means numbers don't look right and tend to wander around unless they're nailed down by slotted rulers and similar tools.) He'll learn Algebra by the time he graduates, and some of Trigonometry, but it takes him considerably longer to do basic arithmetic than most people, unless he has access to a calculator, and even then he sometimes has issues. On top of that, he doesn't know much at all about American History (though he could tell you every one of the Shadow Court family origins and the way their government came about.) His knowledge of music is amazingly good, his knowledge of art is passingly bad and he doesn't know anything about television shows. He speaks Canadian French like a native, Moroccan-accented Spanish (with a slight lisp that isn't Castilian) and English, fluently.
Shadow Dependency
Weakness: using any power that draws on Shadows requires that there be a distinct shadow that Seth is touching (part inside, part outside the demarcation). Fuzzy or faint shadows are hard to work with (require a Good Success vs difficulty 6 or sometimes higher.) Distinct shadows are normally available during the daytime and often at night, and if the sky is visible, for a half-hour after sunset and a half-hour before dawn.
Mystic: Seth is a competent novice spellcaster for the specific spells he knows in human magic but he excels with using shadow. He can turn it into a solid defense, move through it, and create things from it, even a few "permanent" things. He can construct novel "spells" using shadow magic with an emphasis on stealthiness, concealment, and illusion, but also he can pull sharp shadows loose from the thing that casts them and manipulate them. He can use a person's shadow as a means to temporarily control or thwart them. He can make constructs, armor and weapons, though they're not as strong against energy or mental attack. He can see completely in the dark.
His Second Sight can be unlocked to grant him the ability to thwart glamours and illusions, and to see the threads of magic (and other kinds of power and energy).
Shadowbeasts: Specifically, using his Shadow power (outside combat) to make constructs to create animated, independent and pseudo-sentient beings, Seth has found himself creating things that actually seem sentient … and that's a bad thing. Sentient shadowbeasts can choose their own actions and disobey orders and behave based on whatever personality they picked up from the things that cast them before Seth pulled them loose and made them mobile. He can't have more than a dozen of them in existence at a time at this power level. He can make them do minor tasks. When he makes them TOO sentient, he loses control and they will decide whether or not they like him.
Shadowslide: Seth can enter and move from shadow to shadow semi-instantly. He has to touch the shadow to enter or exit, and he still has to move physically, but once he starts shadowsliding he's no longer completely in the mundane world, and it takes more energy to actually touch him.
He can use this to go to the Shadow Courts but ONLY with preparation, not ad-hoc.
He can move very quickly from shadow to shadow, and once IN shadow he doesn't care how sharp the bounds are, until he needs to exit the shadows, when it can be a problem if there isn't a shadow as sharp as the one he started from.
Retreating completely into a shadow lets him peer out at the world.
Note, he can traverse a very long distance by moving between shadows that aren't close together, but they have to be within line of sight from the previous shadow. While he is shadowsliding, he is generally immune to most natural conditions like lack of breathable air, extreme heat or cold, wind and rain, etc. However, extremely hazardous conditions, and intentional attacks, might be able to get into the shadow realm.
Spellfighting:
Spellfighters use brief blasts of the four classic elements as line-of-sight attacks, or create them in place to draw on their innate power. Used in combat, his Mystic skill applies, but out of combat this skill applies. The energy limitations are innate to the focus.
Fire can give light, heat, and can be used for cooking or forging.
Air can be breathed, or can blow directionally.
Water can cleanse, and can be used to trigger healing (healing spell, but if the wound is too great to heal at its level, it won't do anything.
Earth can be used to protect or to nourish plants.
A wand, amulet, ring, or other prepared focus is needed for this technique. The practitioner learns how to make a prepared focus (but may have to find the materials. Seth's usual focus is an ebony or mahogany wand at least five inches long that he keeps under his pillow at night, which activates and dedicates it. It can store power for 3 uses (because 3 dots in the power) and has to be recharged by a ritual that takes at least an hour.
Physical: Seth is trained with sword and gun and can wrestle, grapple, and do aikido/bagua-like things that look almost magical with redirected (kinetic) energy of objects within the range of his grasp. He's quite strong as a human (3 dots) but much stronger in serpent form (full Physical stat.) He's trained with a variety of martial arts weapons but his preferred sword is four cutlasses. He's ambidextrous as far as weaponry goes, and has only a slight preference for his (upper) left hand normally. When he has legs, he's a sprinter — fast at short distances, but lacking endurance past 200 meters running.
Stealth: Not only does Seth move unnaturally quietly, he has no particular scent normally, and if shadow is around, he can camoflage and become hard to see. He's practiced this sneakiness to the point that he can do the Batman vanishing/appearing trick with people who are less sneaky than him.
Snakeshift: (physical) Seth can become a full serpent (no arms, snake head, "horns" not spines) or a semi-serpent (four arms, human head, spines where hair would be on head, snake all the way down below arms) or go all the way to a full human. He can modify his size as a serpent somewhat, up to 20 feet long or short to 10 feet long, scaling his mass up and down proportionally. He hasn't size-shifted as a human. When human, he can keep the scales and spines, or go to skin, except that his head spines convert to stiff thin dreadlocks, and he can have a beard if he chooses. He may develop additional shapes but they'll involve incorporating shadow into his body. He does not have to be in shadow to snakeshift his current form(s). Note that shifting shape will (partially) repair gross structural injuries, but that he can't do it when he's unconscious or otherwise unable to focus on the shift. (He has been known to shift in his sleep in response to dreams.)
Dancing: (physical) if there's one thing snakes are quite good at it's dancing. Even with legs, Seth's a good dancer. He's one of the handful of American-born males who can samba the way that it's supposed to be done. His moves can be hypnotic. (He's been accused of using magic to do this and only sneers because really? No he doesn't. It's a snake thing.)
Drummer: Seth is a good drummer with two arms and a better drummer with four. He can play a variety of taiko and studied kumi-daiko at several stations, but would be considered a novice in Japan. He can also play the standard rock-and-roll drumset of snares, bass, and cymbals, well enough to be in a band. He can even play steelpan, bells, and hammered dulcimer, though not with the same exuberance as the other instruments.
First Aid: Seth has enough first aid training to assess an injury, to know what not to do to hurt someone, and to move or help move them without hurting them. He can stop bleeding with compression techniques, dress injuries if he has appropriate supplies, apply mouth-to-mouth and CPR if absolutely necessary. He can stabilize a broken bone. This lets him know when to use his one healing spell (if he has his spellfocus charged and on him) to kick-start natural healing.
