All excellent questions. Knew they'd be coming up about now.
How does healing work? Will my character`s performance suffer? Does acquiring soul energy affect the healing process?
Your bodies work the same here as they do on Earth, except that they do not need food, water or air to function (so you won't ever feel hungry or thirsty, and your bodies will be fine without oxygenated blood.
Beyond that, if you lose enough blood you will still die. If you are severely injured you will die, and so on. Your wounds will heal naturally over time, as they would on Earth (in most cases). But healing can be done.
Soul Energy does indeed help you heal. Absorbing some of an entity's energy will heal you. For a minor cut like you have just suffered, you won't need much from even an agjonate. But just be aware that those entities need energy too, and you could completely destroy them if you take too much (of course, no one's stopping you from doing that).
Outside of sacrificing entities, you can bandage your wounds using scraps of your clothing, find a spirit or demon capable of healing injuries, cauterise wounds with fire, stitch them up (if you can get a needle and thread from somewhere) etc. Not many options present themselves at the moment but the bite won't do much long term damage if you bandage it.
1) Just making sure I interpreted Shadowguise correctly in that it's a physical change and not just an illusion (which would be what Deceive is).
That is correct. Although more powerful entities may see through your guise and illusions (which could be a disadvantage). You will also be taxed heavily for larger and less human forms, and of course, how long you hold them for. You won't be able to die from it though.
2) I didn't want to just assume that the spell goes off correctly, but assuming that it does (how long does it take once the rote is performed?), I'd imagine I can beat Kane to the lunging attack, otherwise I'll still attack but try to not hit him. Also, I'm going to try and not eat any part of the demon, as I can't imagine that's good for me. Mostly, I'd go for pinning with a bit of puncture or bashing wounds.
Spells affecting yourself usually won't give you any trouble. As long as you write as though you're attempting the spell, and your intentions concerning its use are also presented, I can determine whether it succeeds and what happens thereafter. But usually, shape-changing won't be hard to pull off.
If you think your character is confident with the form you wish to take, it will take less time than something you're not familiar with. I trust you to manage that for narrative's sake.
3) How, exactly, do we shackle demons? I'd imagine that's coming up soon, so is there a thing we have to do or do we just tell you we'd like to shackle it?
Now that there is intention to shackle, I shall explain it.
Shackling and You - What You Need to KnowAs I've mentioned before, the stronger an entity is, the harder it is to shackle. If you can hurt, injure, intimidate or otherwise disadvantage it in some way, you'll have an easier time shackling.
You can attempt to shackle an entity at any time. The process is similar to casting a spell, but takes longer. You need to concentrate on drawing the being into your body, and then defeat it with your mind. Hand signs and invocations help. When you wish to shackle, state that intention and describe your character getting into focus. You need to establish a connection with the entity in question and then pull it through that connection.
Then, I'll tell you if you're successful or not.
There won't really be a back-and-forth between yourself and the entity, so just describe your efforts to capture it, and I'll respond with the being's attempts to resist, and then I'll resolve it.
You can only shackle one being at a time. You can have multiple beings shackled to you, but you can't multi-shackle, if that makes sense. Also, knowing an entity's name will give you an advantage, unless it also knows yours.
Remember that shackling afrits or marids is really not recommended. You can die from that. Or, have your soul consumed. Whichever you prefer