Okay, there are several immortals, and each of them relate to an element (Earth, Air, Fire, Water) I'm trying to use several types of mythical beings/beasts here, if you have any others that I haven't mentioned that would fit in here, could you please tell me?

For the Basic Elemental immortals, this is what you have to imagine for their description. They are neither benign nor malign. Imagine a body for a perfect human being turned into a mold, and fill it with whatever element that is. Earth, air, fire, water. Then remove the mold, and that is their entire physical being.

Earth:

Basic Elemental: Wood-Sprite

Others:
Elf
Imagine someone nearing eight feet tall, about the size of a large branch for an even larger tree. They look very much like a tall, thin tree, they have leaves for hair, and their eyes are very much like bark.
Unicorn
Imagine someone made of pure light, and then cut them in half (vertically). One half is a unicorn.
Basilisk
Imagine a person shape being cut out of autumn leaves. Their eyes are the brightest leaves, and surrounded by two of the dullest,eyelids of sorts.

Air:

Basic Elemental: Wind-Sprite

Others:
Fairy
Imagine a person shape being cut out of the air. That is a fairy. They look, to us mortals, like they are just a space in the air where air is missing.
Pixie
Imagine an absolutely perfect female, shrink them to a tiny size so they could fit comfortably in your hand, change their skin to blue, and make it weathered. Add in dragonfly wings, and you have a pixie.
Sprite
Take a person, cut off their arms, add birds wings, add a beak, and cover them in feathers. This is a sprite.

Fire:

Basic Elemental: Fire-Sprite

Others:
Dragon
Dragons look almost identical to fire-sprites. They are different only in their personality, and that their eyes are as black as coals, not the fire that fire-sprites have.
Salamander
Imagine a piece of coal molding itself into a human like shape, and start walking and talking. That's a salamander, a glowing piece of coal, changing from red to black, to gray, small enough to fit in the palm of your hand, with a very human shape.
Phoenix
Give a perfect woman wings of fire sprouting from her back, eyes of fire, and fire-licked fingers and legs. This is a phoenix.

Water:

Basic Elemental: Water-Sprite

Others:
Mermaid
Mermaids are anywhere from 7' tall, for a short mermaid, to 15' tall for a tall one, on average. They have a human-like shape, with a tale, but every part of their body is covered in scales of one color or another.
Siren
Imagine a perfect woman. Take all color from her skin until it's as white as milk. All color from her hair, until it's blacker than black, and cover her nakedness with a few golden scales here and there across her milky body. Her eyes are the same black as her hair, with normal eyelids as well as a clear eyelid underneath her lower eyelid. This eyelid is what they use when they sleep. It is very handy, as they take in important information that goes past their eyes as they sleep.

Those are my basic immortals so far. And here's my storyline that goes with them.
Immortals are more or less in love with either themselves or their elements. They are, as their overall name suggests, immortal. They don't grow wild, however, for very, very rarely does one reproduce, and when they have the opportunity to, they tend to have no other immortal they love to do it with.

Immortals can become mortals, if they fall in love with one, or become disillusioned to the immortal/immortality/themselves/their element that keeps them immortal. When an immortal become immortal they change to a mortal body, and over-go horrible transformations for a few days until they are completely human, when they have no or very little memory of their immortal life.

Once a mortal, an immortal can only become an immortal again with great difficulty. They have to have their hearts broken, and need to be immortal to heal their pain.

No mortals can become immortal, unless they actually have immortal blood in them. This is very rare, as immortals turn mortal at any time, not just the times when they as an immortal would be changed and ready to give a child to the universe. The transformation to becoming a mortal does not give them the ability to give birth to a child, immortal or no.


The actual story I'm planning for this world, is of a girl who is a mermaid. She grows up mortal, because it was in the mortal world she was hatched, but in her true heart of hearts, she was always born a mermaid. Her mother, a mermaid, fell in love with a man who had taken his daughter out to swim at the beach. She had clutched her egg with her, already fertilized and waiting anxiously to hatch. The egg melted into her during the transformation process, and she gave birth to her soon after. She had no memory whatsoever, but only knew that she must keep her daughter away from the sea.

Immortals know of the mortal world, and some live in it. Mortals know nothing of the immortal world, or the immortals in their mortal world.

Long story short, Lalita ends up going to the sea, and changing into a mermaid as soon as the water's over her head. She loves her new life as a mermaid, and soon finds her father, who tries to kill her. She falls in love eventually with a mortal man. However, she neither wants to give up her immortality to be with him, nor give up him to allow herself to enjoy her immortality fully. She is faced with the hardest decision of her life. The life she never knew she had, or the love she never knew she needed.

A little note on the elements here. The water element beings are the ones who fall in love with humans fewer, because they tend to have colder hearts. Fire beings as well don't fall in love that often, they spar too often. Earth falls in love most, with Air being second to that, and Water last.