EDIT 2019: This was very much an experiment. As such, it might be a bit unbalanced. I might return to this idea for an Eberron release for DM’s Guild. Stay tuned.
One of the experiments of the Daelkyr was to use their symbionts in an effort to create half-Daelkyr hybrids. These beings would live their every day life until dark visions of Xoriat and an alien mindset slowly took over their victim. Never at home anywhere and haunted by dark visions from beyond the void, the Half-Blood is a tragic being.
For the most part, half-bloods look like their parental race. Some have naturally developed symbionts attached to their body in some way. However, it isn’t hard for them to be hidden in some manner. However, some Daelkyr Half-Bloods are more warped by their dark heritage. These poor beings are more likely to go mad by their sick cosmic masters.
Ability Score Increase. You gain +2 to Intelligence and +1 to a stat of choice to signify your mixed aberrant heritage.
Size. Half-Bloods are typically human, but smaller creatures are viable as well. Your size is typically medium, but small size is also possible.
Type. You count as both a humanoid and an aberration. You can be detected by Detect Good and Evil, as well as related abilities and spells.
Speed. Your speed is 30 feet. (25 feet if small.)
Almost Uncanny. You gain advantage on disguise and bluff related checks to specifically come across as a normal creature who was not affected by the Daelkyr. Save for some aberrant quirks (like the symbiont), you look like your parents’ race.
Personal Symbiont. Using your aberrant flesh, you forged your own symbiont from a tumor-like mass of Daelkyr magicks building up in your system. You are granted the Constitution proficiency bonus (or double bonus, if you have this from a class) attributed to Breed Leech. In addition, upon reaching level 4, you may cast False Life on yourself 1/Long Rest, as per the creature’s ability.
However, seeing as you created this being without it needing to attach to you, you do not suffer the drawback of its Attachment ability. In addition, you always have advantage against saving throws provoked or altered by your symbiont (including the disadvantage normally imposed from attachment, making it a wash.)
Flesh Crafting. Your experience with flesh crafting of symbionts allows you to forge them in a fraction of the time it would normally take. You take no more than 3 weeks creating a symbiont and you do not need to be level 6. Attempts to rush the process faster require appropriate checks. However, you must still spend at least 5000 GP to obtain the materials needed to create one.
Unbalanced Mind. Any creature trying to read or enter your mind must make an Intelligence saving throw (DC 8 + Intelligence +Proficiency) or become frightened for 1 round. You may use this once before requiring a short or long rest.
Languages. You understand and speak Common and Daelkyr. You can telepathically communicate with your grown symbiont, as well as other symbionts you might obtain.
Disclaimer: I tried to stay as faithful to the original race as I could, thus balance may potentially be an issue. If you use this, please tell me how it plays! This race has not been playtested as of yet.