Given that 'vampires' is in the title of the webcomic, that I have thus far forgotten to explain how my vampires work here is uh. Anyway.
There are three kinds of vampire in the Otherworlds.
First I need to quickly explain magic. Magic in the Otherworlds exists everywhere in the environment, and living things have magic in them too. Different species need different levels of magic to survive. Unicorns and fairies are at the top of the scale, elves and humans near the bottom. Think of it like heat. Some animals have evolved to live near volcanic vents, others in the snow. Unicorns are the ‘volcanic vent’ end of the scale. There are magical vents all over the planet. More details here
These vampires are made not born. When magic is incorrectly used it damages the caster. If a spell needs more magic than is available in the surrounding environment, it pulls on the magic in the caster. If it uses it all, the caster is killed, but there is small window where they are transformed into a vampire. If they can drink enough blood before that last bit of their magic drains away, they won’t die. This also happens when a magical creature is deprived of magic.
Magical damage is most obviously evident as a loss of colour in the hair and eyes. True vampires have white hair and red eyes. The true vampire’s body stops aging. As long as they get enough blood, they continue to live like a regular person, just y'know, with immortality.
True vampires are exceptionally rare. There are only 4 or 5 in the whole of the Otherworlds.
You have to be a skilled magical practitioner to even use the amount of magic that would damage you, so true vampires are usually highly skilled magical practitioners and know a wide range of spells.
The children of a vampire will always be vampires. But the severity of the condition weakens each generation. This varies a lot, but as a rough guide, say the original vampire needs blood every day, their children will need blood every other day. Their grandchildren will need blood every 3-4 days.
Although, this only really applies when they are an adult. Vampire children grow up biting their non-vampire parent and don’t need a lot of blood, but the amount they need grows as they do. What if they have two vampire parents, I hear you ask? Vampires are usually related to all the other vampires they know, so vampire couples are incredibly rare. The Stollenheims are unusually numerous, with the Le Fanu family after that. The other vampire families are much smaller.
Vampire children learn spells from their vampire parent when they are little, usually designed to help them escape or hide from aggressors… or help them sneak into bedrooms, depending on the morality of said parent. The most commonly known spells are self-transformation and float.
Examples: Hettie can turn into a panther and can float.
Victor can turn into a bat or mist.
Johann can turn into a bat, wolf, a cloud of bats* and use hypnotism**
*it’s more like a cloud of bat shaped energy rather than several individual bats
**only works on people who are half asleep or otherwise somehow out of it.
If vampires need blood, they get tired and cranky, sometimes mildly confused. The longer this goes on, the more tired they get, and they’ll eventually collapse and pass out. They will wake up again, but they will be incredibly lethargic, and at this point they pretty much need someone to shove a vein at them.
They age normally and will live as long as their species normally does. Humans are not the only kind of vampire, this can happen to any caster species - humans, elves, dwarves, fairies, etc. Vampire animals are rare, as animals don't absorb/use magic in the same way. Vampires need caster blood, animal blood is no good to them. Magical animal blood could technically work, but dragon blood is highly corrosive and a unicorn will kill you first.
This is the most basic vampire you find in folklore. A corpse that has been reanimated by a necromancer. A spell is pinned to the body that is activated by a drop in sunlight (or whatever the necromancer sets it to do, but this is the usual). The spell needs blood to keep working, so if the revenant doesn’t bite anyone it will just fizzle out after a night or two. Can also be stopped by the usual – head chopping, burning, stake. Note that the stake is to pin the revenant to the ground. It won’t work if you just jam it through their heart. They’ll just lurch around with a stake through them.