Start with the Thaumaturgy cantrip. At level 3 you learn the Disguise Self spell which you can use once per long rest. At level 5 you learn the Detect Thoughts spell which you can use once per long rest. Charisma is your spell casting ability for these spells.

You have the Light Cantrip. Charisma is your spell casting ability for this spell.

Your Charisma gets +2 and your Dexterity gets +1

Your racial heritage grants you resistance to fire damage and resistance to radiant damage.

Your racial background gives you the ability to speak Common, Celestial and Infernal.

As an action, you can touch a creature and cause it to regain a number of hit points equal to your level. Once you use this trait, you can’t use it again until you finish a Long Rest.

Starting at 10th level, your ancestral abilities have fully merged, you can use your action to unleash your celestial and hellish energy combined. Your eyes burn with a golden flame and two wings of pure celestial and hellish fire sprout from your back.

• Your transformation lasts for 1 minute or until you end it as a bonus action. During your transformation, you have a flying speed of 30 feet and you deal extra radiant damage whenever you attack or cast a spell, the damage you deal is equal to your level.
• Your fiery wings shed a bright light of 10 feet, and dim light of a further 10 feet..
• Once you use this transformation, you can't do so again until you finish a long-rest.