Name: Lucifer or Luci is what they go by, but he doesn't consider themself to really have a name.
Age: Appears to be around their early 30's, but who's to say?
Gender/Pronouns: Nonbinary, he/they
Orientation: Panromantic demisexual
Appearance: Tall, like, eight feet tall to be exact, and with a strong, wide build, softer around the edges but obviously built like a brick shithouse. Luci has brilliant sunflower yellow eyes with charcoal sclera, and inky black hair that falls to his waist that probably hasn't been washed for a while, with all that stresses them out keeping him too busy to. His skin is faintly jaundiced and extremely pale, with stitches and scars abound all over their body. Overall Luci generally just looks like an overly tired trainwreck and really just needs some sleep.
Personality: Cynical and rude, but still very kind and giving. Basically, they'll grumble a bit about things but ultimately are helpful, caring, and pretty chill. Would keep any secret, so long as you are polite about it, and will help you hide the body. Pretty much just a chill dude with some trauma and general jaded perspective idk.
Species of Monster?: Reanimated undead.
Powers?: Essentially, poison doesn't affect them, and he's stronger, faster, and overall more physically powerful than your average human due mostly to the extra muscle and stature. Also they're just hard to kill generally. Also immortal unless directly killed.
Backstory?: Much more similar to the books than the movies. Viktor Frankenstein plays god, and makes his and everyone else's lives hell for it. Overall, not fun. The monster then ruins the lives of the Frankenstein family, and Viktor and Luci eventually chase each other out to the Arctic, where the Isle is then established. Viktor is thought to be dead, having been outlived by his monster. This may not actually be true.
Weakness: Frankly, stabbing them hard enough should do it, but it's hard to get close enough to do so.
Theme song(s)?: ASGORE by Toby Fox has the tragic dad vibes we yearn for.
Other: Somehow, he managed to get a daughter through the same means he was created by.
Name: Eris (like, as in, the goddess of discord. Edgy much?)
Age: Perpetually 16 because Luci thought a teenager would be easier to deal with. Dead wrong on many counts.
Gender/Pronouns: Demigirl, she/it
Orientation: Ohohohohohohoho very gay.
Appearance: Similarly to her dad, the yellow eyes and black sclera of an undead, reanimated punk badass. It wasn't made out of as many parts, hence being a lot shorter at 5'2". It has short, curly black hair, withered umber skin and half of her face is basically just her skull, with one eye still in its socket and perpetually staring in all directions, a bit like a chameleon. She's skinny, and lanky (kinda), and overall not as foreboding as her dad is.
Personality: Kinda just curious about everything. She was never allowed to leave the Isle, and thus is antsy and impatient about everything. It doesn't like secrets, and couldn't keep one to save its life. She's kind, and well meaning, but also legitimately clumsy and prone to berating itself.
Species of Monster?: Reanimated undead.
Powers?: immortality unless killed, and immunity to poisons.
Backstory?: Created, lived at the Isle for years. Doesn't really know much else beyond that.
Weakness: Much easier to kill, because she don't know how to fight for shit. Again, probably just stabbing her should do it.
Theme song(s)?: Would You Be So Kind by Dodie, Froot by MARINA
Other: Has a pet zombie snake named Buddy. She's a Burmese Python, and she's feckin' huge and devoted to Eris.