Updates:
Hey guys! Sorry for the wait, a few days turned into several weeks! xD I got busy with other things and had trouble with the last few injections, which I'll explain in the next post.
After months of on and off work again due to numerous reasons, I have finally finished this mod! This mod is a labor of love that was requested by Shinobu, who some of you may know from the Sims Discord support community. Without their ideas, resources, and support this mod would probably not be here. This is not only my first custom mod with entirely new tunings, but it is also my largest mod to date (not counting file size, that would be No Fade On Everything). It was incredibly frustrating, and took a lot of trial and error, but I’m super proud of myself for finishing it, especially with the amount of detail in it when originally it was just supposed to be some basic buff overlays. I have also learned a lot that should serve well for future mods.
Description
This mod, and I’m surprised no one has made it yet after all these years, is meant to give your vampires and victims blood overlays after feeding. Each bite type that is available to vampires (permission, small drink/casually, deeply, drain life, turn into vampire, uncontrollably) applies a different blood overlay based on the type and a leveling system, out of 4 possible overlays. That means that the more a vampire drinks, or the more a victim is drank from, the bloodier they get! I even made it so that if a sim is drank from too many times, they can die from blood loss. If you don’t want the victim to die just make sure not to cheat or use other mods that allow multiple feedings.
Tier 1 to 4 for victims:

Tier 1 Wrist (Drink with Permission).
Tier 1 Neck (When the sim cleans off or the system reaches this level).
Tier 2 (Drink Casually, Vampire Creation, & Drain Life Spirit; DLS applies a few more points so temporarily appears as Tier 3 before going to Tier 2).
Tier 3 (Drink Deeply).
Tier 4 (Drink Uncontrollably).
Tier 1 to 4 for vampires:

Tier 1 (Drink with Permission).
Tier 2 (Drink Casually, Vampire Creation, & Drain Life Spirit; DLS applies a few more points so temporarily appears as Tier 3 before going to Tier 2).
Tier 3 (Drink Deeply).
Tier 4 (Drink Uncontrollably).
After feeding/being a victim you can either A) wait for the overlays to disappear on their own which take several sim hours, or less, and shows the blood slowly fading, or B) wash it off! Swimming, being in the rain, hot tubs, showering/bathing, and even the vanity table can remove the blood overlays. Victims, after washing the blood off, will still have some holes on the neck for a bit, but they will eventually go away. Vampires have a third option that allows them to brush their teeth and remove the blood that way.
I have also made it so that if you do use mods that enable vampire to vampire feeding, vampires can receive both overlays at the same time. The only area I didn’t add to for vampires is when they turn humans and receive a return bite on the wrist from the turning human. I was making this mod with the thought process that someone might not have other vampire mods installed, or at least not vampire to vampire feeding, so I went with not giving them an overlay during that interaction. If people would prefer their vampires to be bloody on the wrist from their new vampire friend, let me know and I will add it during the next big update.
The blood overlays were created by Natalia-Auditore personally for this mod (thanks to Shinobu) and are included in the package. The overlays are available in CAS and appear as one group under Occult Mouth/Mouth Scars. However, the wrist bite is technically labeled as Facepaint and the neck bites labeled as Occult Neck Scar. There is no visible category for Occult Neck Scar, so they can’t be removed as far as I can tell, so I do not recommend putting them on.
I do have some future content planned for this mod, including a rabbithole interaction where they go to the doctor to be patched up, but these future updates won’t be coming for a while as I need to work on other projects now, like my functional archery range, newspapers, landlines, etc.
Edited Files, Compatibility, & Installing
To install, unzip the file and place the .package and .ts4script file into your mods folder (script mods can only go ONE folder deep). Remember to always clear your localthumbcache when adding new mods or CC to ensure the mods/CC work properly.
This mod is entirely custom and does not override any EA files. This means it should be compatible with all other vampire mods. If you see a compatibility issue, or general errors, or someone made a new bite interaction, let me know and I will look into it.
Created with patch 1.62.67 (April 7th, 2020).
Credits
Shinobu Nox for the idea and supporting me.
Natalia-Auditore for personally creating the blood overlays for this mod!
Scumbumbo for all his amazing work & tools.
Kuttoe & LeRoiDeTout/alphabetsmells for their help in the beginning.
My amazing friend thepancake1 for helping me figure out some workarounds.
And of course my supporters: those following and cecefabbabe_8282, Tina Candela, and SimRealist, thanks for everything!
Translations: French (Arzaz) ; Spanish (alainbardelas); Russian (Origamika); German (Icefire)