Even after death, your soul is unwilling to leave this world just yet. To be a Fallen, you need to be brought back by getting a nat 20 on your fourth final roll on death saves. The difference from a Reborn is that your memories are intact, and you also gain additional traits
Ability Score Increase. Increase one ability score by 2 and another by 1 or increase 3 by 1
Age. You're fighting so you can watch everyone around you die! Think, ********! You'll outlast every fragile, insignificant being on this planet. You'll live to see this world crumble to dust and blow away! What will you have after 500 yrs!? In truth, nothing but power
Alignment. Chaotic in nature, mostly good or evil, rarely neutral
Size. Same size as the body you once had before
Speed. Your base walking speed is what you had
Darkvision. You can see in the dark within 60ft
Undead Nature. You walk the thin line of living and death, so now considered undead and humanoid. You have advantage on saving throws against poisons and are resistant to poison damage. You don't need to eat, drink, or breathe, now immune to diseases, don't need to sleep and can't be forcefully put to sleep.
Past Life. Since you are 2 races, you can still choose race related feats
Fallen's Will. You can add your Constitution modifier on saving throws against any effect that only affect undead and now have advantage on death saving throws
Languages. You speak whatever you spoke in your past life
Living Flame. You are resistant to fire damage and immune to Extra Cold damage
Flaming Bode. The fire covering your body doesn't burn you and your equipment. Emitting 15ft of light which can be expanded to 30ft by using a bonus action, it deals a quarter of your level d4 fire damage
See no Darkness. At level 5, your flames are capable of dispelling the Darkness spell if its 3rd level or lower
Stalking Shadow. You have proficiency in stealth and are able to use a bonus action to Hide in dim light or darkness
Umbral Magic. You know the Minor Illusion cantrip. At 3rd level, you can cast the Shadow Blade spell with this trait. At 7th level, you can cast Hunger of Hadar. You can't cast this spell with this feature again until you finish a short rest
The Enemy of my Enemy is my Friend. You are resistant to necrotic damage and advantage against being charmed and frightened
Same Kin. Undead seem to recognize one within their own. Undead with an intelligence of 8 or less will not attack you unless you attack first. Undead that are controlled by the Wight's Life Drain ability or resurrected by the Animate Dead spell are not affected by this trait
Unyielding Soul. You can use your bonus action to fortify your body. This transformation lasts for 10 rounds (1 min) or until you end it as a bonus action. Whenever you take damage, you reduce it by your level
Unyielding Will. become resistant to it for 3 rounds. Once per short rest.
Raging Soul. You can use your action to unleash the inner rage within youself, causing a fearsome aura to emanate from you, with your eyes glowing vibrant flames. It lasts for 10 rounds (1 min) or until you end it as a bonus action. Whenever you take damage, you reduce it by a quarter of your level rounded up. In addition, you deal extra force damage to a target when you deal damage with an attack or spell. The extra damage equals to your proficiency bonus. Once per long rest.
Living Flame. You are resistant to fire damage, but also have disadvantage in stealth checks
Emberfeel Magic. You know the Green-Flame Blade or Fire Bolt Cantrip. When you are 3rd level, you can cast Hellish Rebuke spell once per long rest. When you reach 5th level, you can cast the Flame Blade or Scorching Ray spell once per long rest.
Darkness Consumption. You have proficiency in Stealth and can use a bonus action when in darkness to make all terrain that is the same darkness difficult. The affect ends when you leave the darkness or use an action to end it. You can do this equal to your proficiency bonus per long rest
Shadow Stalker. At 3rd level, when in darkness, as an action, you can enter the shadow you're in and walk thru it, but still can be discerned. While inside, you are under affects of the Pass Without Trace spell and you can see and hear the outside a number of feet equal to 5 x proficiency bonus. When you enter an area other than darkness, you exit it automatically, or can use an action to leave. Once per long rest.
Life Robber. When a creature within 10ft of you is killed and has a soul, you can use your reaction to absorb it to regain hp equal to your level. If you heal more than you have, then it becomes temporary hit points. This also makes the creature unable to come back to life unless it can live without its soul. You can use this feature equal to 1/3 of your proficiency bonus rounded up after a short rest
Soul Giver. When a creature makes a death saving throw within 30ft of you, you can alter its fate. Use a reaction to make the creature regain a number of hit points equal to your level and the cost of you taking the same amount of damage. If you are killed this way, you don't come back at all unless its a wish spell. Once per long rest
Pseudo-Spectral Limbs. If you have a severed limb and hold up to the stub, you instantaneously cause the limb to knit to the stump. After 24 hrs has passed and the severed part wasn't reattached, your body instead creates a version of the missing limb, spectral like in appearance, but still physical.
Unending Life. When you are reduced to 0 hp, you can make a CON save (DC equal to the damage taken and difficult of it). On a success, you instead drop to 1 hp. Once per long rest.
Special Feats
Soul Projection. You learn the Find Familiar spell and can cast it as a ritual. Your familiar is a Specter, with it being a undead, instead of a Celestial, Fey, or Fiend. While seeing through your familiar's eyes, you ignore it's Sunlight Sensitivity trait
The Past Never Forgets. You can choose to gain 2 traits from the Race chosen in the Size, Speed, Past Life and Languages traits. EX/ Fallen Changeling, you can pick the Shapechanger and Changeling Instincts traits
Overwhelming Emotions. As a reaction to being dealt damage, you can deal half the amount of damage rounded up in physic damage against the attacker, as long as you can see them. You can use this equal to half of your proficiency bonus after a long rest
Legendary Race: LV 21
+2 any one, +1 any one, or +3 one stat
Dark Walker: Able to use shadows as a mean of transportation within 40ft