Your Charisma score increases by 2 and your Constitution increases by 1. 

Arkosios are born imparted with knowledge from both their parents. The birth of an Arkosios always leads to the death of the mother. Arkosios physically mature to adulthood over the course of an hour after birth. There is a sense of unfamiliarity and oddness as they learn what it means to be alive. Arkosios don't visibly age and have never lived long enough for their lifespan to be categorized due to the nature of their treatment.

Arkosios do not have an innate tendency toward neither evil or good, although their very natures push them to the chaotic alignment.

Arkosios are about the same size and build as humans. Your size is Medium.

Your base walking speed is 30 feet.

You can speak, read, and write Common and Infernal.

Thanks to your demonic heritage, you have superior vision in dark and dim conditions. You can see in dim light within 60 feet of you as if it were bright light, and in darkness (magical or otherwise) as if it were dim light. You can’t discern color in darkness, only shades of gray.

 You have resistance to necrotic damage and radiant damage.

You know the thaumaturgy and light cantrip. [3rd] You can cast hellish rebuke (2nd) and lesser restoration once per long rest. [5th] You can cast darkness and daylight once per long rest. CHA is your spellcasting ability.

Starting at 5th level, you can use your action to unleash the chaotic energy within yourself, causing a searing light to radiate from you. The instant you transform, other creatures within 10 feet of you that can see you must each succeed on a Constitution saving throw (DC 8 + your proficiency bonus + your Charisma modifier) or become blinded until the end of their next turn. As the light subsides, your eyes burn the same color as your angelic parent granting you truesight for the duration. Black feathered wings sprout from your back. These wings allow a flying speed of 60ft. In addition, once on each of your turns, you can deal extra radiant (or necrotic) damage to one target when you deal damage to it with an attack or a spell. The extra radiant (or necrotic) damage equals your level plus your proficiency bonus. Your transformation lasts for 5 rounds or until you end it as a bonus action.