Fellwarped have both physical and mental changes brought on by their time spent in the shadowfell. Due to such changes they have a +1 to the scores of dexterity, charisma and constitution, they are agile, beautiful and rarely get ill. But this is not without its caveats, the time spent in the fell has warped their minds, thus they have -1 on their wisdom and intelligence scores.

While in the Shadowfell, they age at half the rate of a human, while on any other plane they age and mature at the same rate as a human.

Fellwarped are most commonly neautral alignments when found in the Shadowfell. They kill to survive, and they obey the laws of their people. Outside of the Shadowfell they often fall towards evil, relishing killing for pleasure, and often the laws they are used to don't coincide with human laws.

Fellwarped have are very similar size to humans.

Fellwarped are slightly faster than humans, an ability granted by the danger of the Shadowfell. Your base walking speed is 40 feet.

Due to lack of sunlight, or any light for that matter the Fellwarped adapted new ways to see. Their eyesight has grown very limited. Though they can see, their eyesight is primarily based on movement, and as such they cannot make out small details. They can also no longer determine colour, and their sight is restricted to only being able to see varying shades of white grey and black. 

This led to the evolution of the ability to echolocate. Their hearing became twice as powerful as a humans, and they gained the ability to hear frequencies that humans cannot. This is coupled with their ability to create a sound only they can hear that they can use to see in pitch black and even magical darkness. As such they can fight without the need to see as long as they are not afflicted by, or in the radius of magical silence. The cone of vision created by their echolocation is approximately the same as a human's eyesight. 

As such they also cannot read unless by touch, and can only determine the difference between materials that are very different, for example they can tell the difference between stone and metal, but not the difference between steel and brass.

They also created their own written alphabet with broad runes that can easily be read by touch, and is written by scratching the material rather than staining it. ( Eg. scratched paper instead of inked)

Due to being so conscious of sound they slowly began to move more quietly, with each generation becoming more and more silent. You have an advantage on stealth checks.

Fellwarped became adept predators, with a new found strength in catching their prey. With the loss of sight they lost the ability to aim down a bow or crossbow, giving them a disadvantage to hit on all bows and crossbows, but they are adept at catching their prey on foot and thus have a proficiency with all bladed weapons that possess either the light and finesse properties.

Fellwarped developed a strange predicament. While in the shadowfell they do not need to eat, they gain energy when they kill other creatures that live in the fell, they can go almost a month without needing a kill, and will often bring back creatures to their clan so that younger fellwarped can be given energy, and are also taught how to kill. While in the shadowfell they age at half the rate of humans.

When a fellwarped leaves the fell and enters any other plane, they begin aging at the same rate as a human, and they also require food and must eat at least once a day, or like a human, start to weaken. Fellwarped can only eat meat, and the meat cannot be any less fresh than a day old. Anything other than this will make them sick giving them a -2 to dexterity and strength and halving their movement speed until they are able to eat some good meat.

Many fellwarped are strangely drawn to human meat, often needing to resist the urge to slay and eat a human should they be found alone. Many do not resist this urge.

Should a fellwarped eat human meat rather than animal meat they are bolstered in both their strength and dexterity, gaining a +1 to both for the next day. This feeling is like a surge of energy, they feel elated and incredible. Should a fellwarped eat human meat it will be almost impossible for them to go back to eating animals.

Due to their link with the plane fellwarped have the unique ability to return to it. While outside of the shadowfell once a week fellwarped are able to return to it, though this cannot bring them back out and so other means are required should they need to leave. Most fellwarped communities have a single conjurer who is able to send fellwarped to mortal plains, though this is a rare occasion and being sent away from the shadowfell is rare and almost exclusive to banishments or very important missions. If a fellwarped is on another plane and is reduced to 0 hit points and fails all 3 death saves their ability to travel home is automatically used and they are sent back to their community and are considered stabilised, saving their life, but just barely, and again leaving them stranded in the shadowfell. If an exiled fellwarped is sent home often they will be executed upon discovery.

To a human a fellwarped has a strange and fascinating beauty. Like a drop of blood in a patch of snow. Like a flower growing deep in a cave with no light. Something that isn’t quite right, though you can’t look away. As such humans will often become fascinated with one should they meet them, and it is not hard for a fellwarped to manipulate them because of this. This effect is not found in other races such as elves or dwarves, and is most likely due to the link fellwarped have with the human race.

You have the ability to cast charm person once per long rest. The target must be a human otherwise it has no effect.