Alright. I'm glad we could work that out! Here goes...something...
This spoiler is for discussing the Shadows and how the summoning-them ability works.
I decided I'd model it as being able to summon a specific shadow (of a given type) which happens to be unkillable. This means that no matter how many times you summon a shadow and it dies, it'll reform and be summonable again. Feel free to ignore this mechanical artifact and have Tobias summon separate shadows each time, though.
The Ally advantage has a base cost depending on the point cost (ie, power) of the ally relative to you. This cost is multiplied by an amount varying based on enhancements added. For this, Summonable is a no-brainer. It lets you roll to summon a shadow; if you fail, you can't summon him for a whole day, but if you succeed, he's around until you dismiss him. I thought a bit about it, before deciding that having them stick around for no longer than half an hour per summoning and be summonable after a failure were slightly on the stronger side, but not enough for more than a convenient rounding-up. I also added the Minion enhancement (because whether or not they're "minions" per se, they're intelligent, free-willed beings who are yet in sufficient awe or somesuch to follow Tobias's commands without needing him to worry himself about keeping them happy). I next added an ad hoc enhancement, the inverse of Untrainable, so I could fiddle the summoning back into the magic system. Overall, without other modifiers, such summons cost triple the base amount from points. That's important for non-Tobias people. For the record, this means that summoning a being as powerful as you with no roll required would cost 60 points--more than half of your perks! Oh, and it would get your character considered an immediate balance threat, especially if said character could also summon more things.
But back to Shadows.
All Shadows have some traits in common. First off, Shadow Form for -20 points. This restricts them to creeping along walls and floors like, well, shadows. In addition, it increases light-based attacks' damage by 50%. On the bright side, the disadvantage halves all physical damage and lets them move across walls and ceilings in a gravity-defying manner, and slip through cracks and such due to being two-dimensional. Next, I'll give them x2 Vulnerabilities to Fire and Light attacks for -30 and -20 points, respectively. This will mean that light-based attacks deal triple damage, not double, but A. there wasn't another way to finagle it and B. it seems logical that light-based attacks, presumably specialized for dealing with creatures of darkness, would be more effective than fire. (But mostly A.) They won't be manipulating anything with their "physical" bodies (more on that later), so let's give them No Manipulators. Add in Social Stogma (Monster) for -15 points because seriously how would a weird shadow monster be able to interact with normal society, and they have a total of -145 points, which means they can spend another 145 later. Let's start doing that.
First, Injury Tolerance (Diffuse). It means that attacks based on poking you (like spears, bullets, and curious children with sticks [okay, those would probably be Crushing unless they sharpened the sticks, but that's not important]) deal no more than a single point of damage, while other physical attacks don't deal more than two. Add in the Shadow Form, and all physical attacks deal only a single point of damage! It doesn't come cheap, though--100 points base, with me assuming that magical attacks which don't affect diffuse things are balanced by nonmagical attacks that do (ie, explosions, area-of-effect, etc). At this point, they have so many halvings that I'll just say they're immune to physical damage (except for magical weapons, which I'll let scratch them). They also get Unkillable 1, which is 50 points. That should be quite sufficient, for the "base template". To summarize, all shadows have:
-Injury Tolerance (Diffuse)
-No Manipulators
-Shadow Form (constant)
-Social Stigma (Monster)
-Vulnerabilities (Fire, Light; both x2)
-Unkillable 1
This package costs the five points total.
Now, then. Shadows also have other abilities. Let's give you one each of 25, 50, 75, 100, 125, and 150-point shadows (which have the shadows traits plus some other ones). Let's go over them one by one.
Telekinesis is an important one. It lets them interact with the world. It costs 5 points per point of GURPS ST equivalence; I'll charge 10 per point of Unnamed System Strength. It also has some modifiers. First, since it's supposed to represent them sticking shadowy appendages into the world, it's Visible (reducing cost by 20%) and has only a single yard of reach (still longer than most arms; -30%). Some Shadows might have longer ranges; if so, it's noted. This costs five points per level.
Next comes ways to harm enemies--a Shadow Touch. First, an Affliction for Blindness, which reaches as far as the telekinesis (for the same reasons). It, um, blinds people (if they get hit and fail the resistance roll) for 30 seconds per point that they fail the roll; between the +50% for blinding and the -30% for being melee range (well, it was a bit of a hack, but it was in your favor), it costs 12 points. Stronger Shadows can cause severe bruising and aversion to darkness, as well.
Very strong shadows can possess people, and become less subtle (and all the more terrifying for it).
Finally, a bit of Terror given to the stronger shadows for their...scariness. This costs 30 points, -20% because it can't be deactivated, -10% for being magical in nature (and hence inhibited by antimagic fields and such), and -10% again for the fact that some people can develop immunity (Tobias, for instance, but also experienced monster hunters), making it 18 points.
I'll be assuming that the shadows have an equal number of stat points and PP. In fact, that's my default assumption!
25-point: Shadow Package [5], Shadow Touch (Default) [12], Telekinesis (ST 1) [5], Terror [18], Cowardice (9) [-15]*
*I couldn't get everything to fit otherwise. Basically, when threatened with the prospect of intense personal harm, they have a 60% chance of chickening out. If they're dragged into combat, they'll fight despite it, if they're threatened or cornered somehow. (They won't like it, but...)
50-point: Shadow Package [5], Shadow Touch (Default) [12], Telekinesis (ST 2) [10], Terror [18], Chill1
75-point: Shadow Package [5], Shadow Touch (Default+damage2) [17], Telekinesis (ST 3) [15], Mana Dampener3, Terror [18], Improved Chill
100: SP [5], ST (2-yard, Default+damage+darkness aversion4) [19], Telekinesis (ST 4, 2-yard reach) [24], Improved Mana Dampener, Terror [18], Bright Shadow4, Improved Chill, 3 unspent PP screw it
125: SP [5], ST (2-yard, Default+damage+darkness aversion+sleep) [19], Telekinesis (ST 46, 2-yard reach) [?], Improved Mana Dampener, Terror [18], Infections Attack6, Bright Shadow, Improved Chill, Pierce Glass7
150: SP [5], ST (2-yard, Default+damage+darkness aversion+sleep) [19], Shadow Possession [15]7, Telekinesis (ST 4, 2-yard reach) [], Improved Mana Dampener, Terror [18], Infectious Attack, Bright Shadow, Improved Chill, Pierce Glass, -15
1: All but the weakest shadows can lower the temperature of their surroundings. They can affect a four-yard radius within 10 yards of themselves, and decrease the temperature by up to 20 degrees at a rate of two degrees per second of concentration. More powerful shadows (those with Improved Chill) double the maximum difference and the rate to 40 and four degrees;
2: As a normal magical attack, except...you know...shorter-ranged.
3: Mana level is effectively lowered by one step when aimed at a shadow, due to it absorbing the magic or something. This gives a -2 on rolls to use magic on them--specifically, the Magic vs. Resistance ones. This penalty also applies to rolls by any magician who the shadow is holding, regardless of what the target is. More powerful shadows (those with Improved Mana Dampener) apply this effect to any mages within a yard of themselves.
4: The victim temporarily becomes terrified of darkness, unable to willingly come within about ten feet of shadows and unable to do anything but retreat if they get that close or closer. (This is Dread (Darkness, 3 yards).)
5: A perk that makes them that much more visible when they want to be, making it harder to miss them when they want to terrify people. It doesn't interfere with their ability to hide, though. (Based on Penetrating Voice.)
6: Shadows start to hit a "strength cap" at a certain point; their insubstantial limbs can't be quite as strong as real people, except for the most powerful shadows.
7: A shadow of this level can move through glass barriers, allowing them to more easily move about through windows and such.
8: The attack of very strong shadows carries a bit of a drawback. If someone is killed by it, they come back sunset after next as a shadowspawn, with most of the basic Shadow Package except the actual shadow form (although they are still made of shadow, and hence only take 1 damage from physical attacks not more effective than average against them), plus they have the basic (blinding) Shadow's Touch. This is a downside because the shadowspawn are still free-willed and in no way tied to any existing Shadows (or Tobias), and they're not going to be happy about being turned into a monster.
9: Shadows' Possession has a number of qualifiers. As per standard GURPS possession, they need to be in contact with the subject; I'll rule that this means that the shadow's actual shadowy bit needs to be in contact with the subject, or at least his shoes, and give them a 5% discount for their trouble. You also need to concentrate on the possession for a turn, which means no using Shadow Touch or telekinesis or anything that turn. If the host resists, that particular shadow can never attempt to possess that particular person again. -10% for not getting memories, -20% for being clearly affected by the possession (with Social Stigma (Monster) and some extremely Unnatural Features), and -25% for taking mana (10, to be exact). Another ad hoc 15% based on the Spiritual limitation: They can be exorcised with typical methods, and if the victim is hit with lasers, light magic, or the like, the shadow takes an equal amount of damage to what the host does (or, if it doesn't affect normal humans, what it would do to the Shadow if it lacked its light vulnerability), while if the host is hit with flame, the shadow takes half the damage the host does. It now costs only 15 points!
Now for the easy bit: Figuring out how much each one costs. Here's how I'm doing it:
1. Compare strength of summon to strength of character.
This is pretty simple. It'll work like the table on page 37 of the GURPS book. Pretend that there's an entry for 125% that says "8 points".
2. Figure out an appropriate Frequency of Appearance given the stated difficulty and the character's Magic
Basically, figure out how likely it is that the character will succeed on summoning the creature based on the Target Number. The likeliness contributes to a modifier based on percentages:
100%--x4
95%--x3
90%--x2.8
80%--x2.3
75%--x2
66%--x1.8
50%--x1.3
40%--x1
33%--x0.9
20%--x0.75
10%--x0.5
Round everything up to a reasonable fraction. I'm being nicer than GURPS by allowing such a fine series of gradiations.
3. Apply Modifiers, then Round Up
Applying the default, refined Unnamed System summon rules applies a +200% modifier. You can summon the creature with a successful Magic roll at any time, and it has to follow your commands until it leaves when either dismissed (which automatically happens when the summoner goes unconscious or falls asleep, unless they get along) or at the end of a half-hour or so (though with a good relation between summoner and summon, the summon would be able to perform tasks in its own realm for longer than that). Fiddling with these basic rules, whether by adding more of a mana cost, increasing or decreasing the casting time (default: 1 turn) or time staying, or something else, adds additional modifiers. Once all the modifiers are added, multiply the cost appropriately and round up any remaining fractions.
4. If applicable, apply Alternate Ability rules
This is going to cost a lot. But have no fear! By saying you can only have one summon summoned at a time, you pay full cost only for the most expensive and 20% for the rest! If you can summon two at a time, pay full for the two most expensive and you get a discount on the others, and so forth. This should make summoning cheaper. Since I'm feeling generous (and all the rounding's been against you so far), you can round down as long as you're paying at least 1 point for any non-negligible summons. ("Negligible" is in the eye of the beholder; if your summons are all woodland creatures, a wolf isn't negligible, but if you can summon, say, 200-point incarnations of various natural forces, it kinda is.)
So let's apply this to Tobias's shadows.
25: 1*4=4
50: 2*2.8=5.6
75: 3*2=6
100: 5*1.8=9
125: 8*1.3=10.4
150: 10*0.9=9
Next, since we don't have any special changes to the summoning rules, we simply triple prices. 12, 17, 18, 27, 32, 27. All but the 125-point summoning get divided by 5. Total cost: 2+3+3+5+32+5=50. That...wasn't intentional, but it's convenient.
Ugh. That took so long, and got interrupted so many times. Here's hoping it works! And those shadows
, figuring out their powers took up most of my time. I'll let Projeck deal with their stats, with the reminder that he probably doesn't need to give them Strength.
Heh. That had better not happen this time, especially given the potentially battle-changing effects some of them have. Blindness and such for the weakest, things like possession and save-or-lose for the stronger ones...
Although with only one unit at a time, it'll be easier.
Yup. It's inspired a new Tidbit from me:
4. With the dawn of what some are calling Mithril Age of Space Travel, putting a satellite into Low-Earth Orbit and even higher orbits became much, much cheaper. This lead to a proliferation of satellites for various purposes, from major (allowing all locations to receive satellite-based telecommunications and surprisingly fast Internet) to petty (an array of geosynchrous communication satellites which keeps one over a given city at all times). Unfortunately, collisions between satellites, often involving so called pirate satellites put in orbits without proper permission, have caused many to believe that Kessler Syndrome is going to be coming into play shortly. It is feared that this could destroy countless satellites, crippling much of the global communications network, especially in poorer countries, and possibly even leading to spacecraft debris crashing to Earth. A spacecraft sent up to try and curb the issue by safely de-orbiting defunct or illegal satellites was famously struck by another satellite within hours of deployment.