Succubi (Only female)
(Avoiding smut with Succubi's and Incubi's is impossible, so skip to Nymphs to ignore the smut stuff)

Appearance

Skin color: All shades of pink/red
Extras: Horns (Color of your choice), Tail (Same color as the horns)

Powers

They're basically demons, so they have the same (Super strength, fire related powers, can change their age to decieve humans, and can change their appearence human-like) however they have added powers regarding lust (Can change their body shape, can get power boosts from lust) and instead of feeding on souls, hate, and anger they feed on humans love, lust, and adoration for them. You can easily tell if someones a Succubi since they'd have a long trail of needy hearts behind them.

Incubi (Only male)

Exactly the same except they're only male, and can only have every shade of red as their skin color. As an edition a Succubis can not take power from an Incubi and vica versa (And a Succubis can't take power from another Succubis as an Incubi can't take from another Incubi)

Nymphs

Appearance

Skin color: Usually any shade of green, most commonly forest green, hoever can be a human skin tone as well

Information

When a Nymph is born, they're born in a plant or tree. They can either be physically attached to the tree or plant (By their hair or other) or else they just can't be too far away from their plant or tree or else they'll get extremely sick and die. If their tree or plant dies, they die, so they'll protect it with their life.

Powers

Can feel pain of their tree/plant, Can pop inside and outside their tree/plant to hide, they die with their tree/plant

Mermaids

Appearance

Skin color: Normal
Tail: Can range from any shade of green, blue, purple, pink

Powers

Can breathe underwater and on land (However they can't walk on land, and they can dry up), can talk to sea creatures, won't get crushed if they go too far down

Vampires

We all know them. Bloodsucking Vampires, can't go in the sun, can become a bat, blah blah blah.

Demons

Appearance

Skin color: Can be every shade of dark red to black
Extras: Horns (Can be a dark brown to black) tail (Can be any shade of red)

Powers

Super-strength, Fire related powers, Can change their age, and Can change their looks to more human-like ones.

Witch

This I don't need to explain. As long as you train and study hard, you can do anything with magic. Its all treated the same.