Info on Derek's brand of vampiric infection
A lot of this is head canon based on not only the movie, but the prior movie and book, because there's a lot implied but not spelled out throughout the entire series (and it's occasionally contradictive as well).
1) It's both viral and demonic in nature
a) Viral because it changes the body and can be put into stasis by 'an experimental AIDs drug' (But not cured--this is all canon from Derek's movie), and of course it's entirely blood-bourne on the physical side of things.
b) Demonic because according to the first movie (and somewhat touched on in Derek's movie), vampires were created when a group of excommunicated priests did a 'reverse exorcism' on themselves in an effort to gain immortality. It's also heavily implied in the original book that the source of the vampires is demonic in nature, which is why the Church is so involved (and actually the main source of vampire hunters for that story).
c) There are three ways to transmit it: Derek can bite you or scratch you (it has to be hard enough to draw blood), or you can inject yourself with his blood (Derek became infected by using the blood from Zoe's transfusion in order to infect himself so that he could get into the vampire's nest without being detected by them). Nowhere in canon does it say that his/vampires and other infected people's spit or other bodily fluids can transmit the disease part unless it enters the bloodstream, so I'm assuming those are the only three methods that will infect someone. Which, really, is bad enough, if you think about it. So, it's okay to kiss him (or have sex with him, if you're brave enough to try it). Just...stay away from the blood aspect on either side.
All this means that someone can both trace the progression of the virus component through normal medical means, and also that if your character has the abilities (I would imagine that would include most gods, angel/demon types, hunter types that have 'otherworldly/supernatural senses', etc.), they'd be able to sense the demonic taint on his soul, and the fact that it's trying to devour his soul and replace it (much like the virus is doing to his body). Derek himself is actually a pretty nice guy and on the 'light' side of things, and his own soul would show that if inspected.
2) Other traits of the virus (canon):
a) Derek is still living, although his vitals are skewed, with a body temperature of 41 degree fahrenheit, and an average pulse rate of 45 beats a minute (Temperature is movie canon; pulse is a guess based on Zoe's heartbeat when Derek can hear it and a conversation they have about it when Derek is justifying letting himself get infected; it's heavily implied the pulse slows way down).
b) He gets cravings for, essentially, raw read meat, although since he's in stasis, that probably won't be too pronounced unless he gets sick, injured, or worn down.
c) He has heightened hearing, sense of smell and very good low light vision thanks to the infection. Yes, he can hear your heartbeat and smell you from several yards away. If he's not feeling so hot, your pulse and the smell of your blood may end up making you a little too attractive to him, so it's a good idea to treat the guy with caution in a situation like that.
d) Again, when he isn't feeling too hot (or if the stasis on the virus is lifted), sunlight can make him irritable (canon from Zoe's little speech on her own condition).
e) It's implied in the first movie that eating and staying awake helps to slow the virus down. I'm ignoring the sleeping part (because as a human, he'd need his REM at some point so he doesn't, you know, go insane), but I am using the eating part because it makes sense; his body still needs food, and since it would need to be close to normal human temperature to digest what he eats, I'd guess the temporary rise in said temperature helps to 'fight back' against the virus and maybe destroy some of the invading cells.
3) What will kick Derek over into being a vampire:
a) He dies.
b) He bites and feeds off of someone (this will speed the process up, so it's not instant, but he'll probably lose his mind and his humanity at that point, which pretty much seals his fate.)
c) He gets fatally bit by another vampire (although if he gets torn apart, he might not come back. Canon is iffy on this one and it seems to be a 'dramatic' decision as to whether or not it works).
d) The Malnosso's stasis on him goes away and he suffers through the last two days of infection.
4) Signs that Derek is 'having problems'
a) He'll get pale and sickly looking.
b) He'll get very fascinated with blood and wounds.
c) If it's bad enough, his eyes will
turn black d) He will 'pop his fangs' and grow 'claws' (IE: He'll get a sudden, over glorified, pointy manicure).
5) Mind control and other funky stuff (IE: Pick and choose your own canon because, well, it's messed up something awful.)
a) In book canon, vampires have mind control abilities, including making people hallucinate, the Voice, and making their victims do exactly what they want (and a lot of it involves making use of the human lust centers). Their bite also causes an 'addiction' of sorts in their victims which makes them want more of the same, although it fades away the longer the vampire is away.
b) In both movies, victims have a 'link' to the vampire that bit them, which can be used by both parties to 'see' what the other is doing. On the human end, it's pretty unpredictable and usually a bit disjointed. On the vampire's end, there's really no clear idea of how well they can 'see' what's going on, but the vampire can definitely 'control' their human--at least well enough that the human will follow set instructions and hide their infection from their follow humans.
c) Derek also somehow manages to get 'linked into', and it's how the master in his own movie finds and kills the other hunters Derek is originally sent to recruit (although the vampire for some reason can't seem to pick out what Derek is actually thinking or planning in any other regard--she just seems to know where he's going and gets there before him). It's hard to say if Derek actually manages to 'block her out' once a priest explains to him what's going on, but the master does fall for several of his baiting tricks later on, so it's entirely likely. She also manages to hit him with a pretty nasty hallucination the first time she touches his mind, but that's the only time it happens (After that, Zoe gets all the 'visions' of what the master is doing at any point and time).
d) How long it takes to fall victim to the infection varies greatly from canon source to canon source. In book canon, there's no set time (many of the victims are 'led on' for months, in fact. By contrast, the hunters have a whole little stake/behead/burn/have the bishop say a prayer over you thing going on that they tend to do as soon as they can manage it, which indicates a fast turn over once you're dead). In the first movie, it seems to be only a few days before you go over. In the second, it's the same way; they make it obvious Zoe has very limited time once she loses her drugs (The day after she loses them, she's really sick and the local village nurse gives her a massive blood transfusion to stave off the inevitable), but again, there's no set time mentioned. For head canon's sake, I picked the traditional 3 day time span.
I may add more if I run across more canon, but that's the gist of Derek's Vampirism And You. Feel free to ask questions. :)
And now, for the basic permissions:
What's okay
Unless a post says 'locked', 'narrative' or specifies that it's for specific characters only, feel free to respond. Derek will talk to anyone at least once. Thread jacking and hopping is fine, too. I can take it; I've been in nexus RP for years XD.
You can touch and hug him (if he likes you, he's likely to respond in kind). Kissing on the cheek and forehead is okay. Expect him to jerk back though if you try for anything intimate. And then he'll probably put a nice distance between you, just to be safe.
You can try and start a fight with him, and if you succeed, I'll do my best to go along with whatever happens, unless you plan to hurt him badly or try and kill him. At that point, a nice OOC chat would be appreciated before hand. I'm pretty okay with injury; killing though...well, there better be a good plot reason for it, you know? especially since death for him means dying and then coming back as an actual vampire, which would be bad for all involved.
Also as a note; he's not likely to start a fight without a damn good reason. We're talking someone is going to die or get badly hurt if he doesn't do something reasons.
He might be open to romance...if you approach him right (Hint: He likes girls that will tell him off when he's wrong, but he's likely to treat clingy and dependent girls as little sisters at best.). Keep in mind though that he has a hang up about people around him dying; it'll take awhile for him to decide it's okay to allow it (We're talking weeks and possibly months, here. No insta-lurve for this guy). He's also about as straight as you can get, so bro-mance isn't going to happen, either. He's okay if your character is into that sort of thing...just...not with him, thanks.
He will not willingly infect someone else. Ever. And the only person he'll be willing to give blood samples to is Bones, pending getting that set up with his mun. Try it, and you'll see the fastest disappearing act ever recorded. (Which means, mun is cool with it, but Derek himself will have a spaz).
Curing Derek is kind of a sticky thing. Considering the nature of the infection, I'd imagine it would take a pretty hefty effort to free him of it--you'd have to both halt/cure the virus and find some way to detach the demonic thing from his soul without damaging the soul and/or killing him. So I'd expect there'd be a heavy price for anyone who would want to try. This would be one that I'd definitely want to have an OOC discussion about before hand, and possibly even have to check with the mods to make sure we weren't breaking any Luceti limits power wise.
What's not okay
Honestly, I'm good with most things. No god-moding and the like is usual for most players, so I feel it doesn't really need to be said, and if you're not sure about something, feel free to PM me (email is faster than IM since I only hop on AIM if I'm pretty sure someone wants to talk to me. Just click on the 'email' option in Derek's profile. :) ).
Just about the only things I wouldn't agree to is a male/male romance (I'm not against slash, but I also want to keep Derek canon in that regard), and someone god-moding Derek into dying (or actually, infecting someone--that's an issue we should probably take to the mods for approval before we did it since it could be potentially very destructive to both the Luceti population and the main plot arc on the whole.).
I'm up for OOC planning and 'what if' brain storming, and just about any character/genre. Just let me know. :)