Pride Before the Fall

Pride Before the Fall: You lost everything, and in your vengeance and grief betrayed a celestial being tied to you. In your own ways, you have fallen, and doing so has given you newfound abilities. Additionally, your deal with the devil Gazra/Fierna (idk its part of Rachel’s thing too) has added to your capabilities.

• As a bonus action, if you use your divine smite feature, you can change the damage type to fire damage, calling forth the energy of the nine hells.
• As a bonus action while you have your Radiant Consumption feature active, you can change your Aasimar manifestation to that of a fallen aasimar - Necrotic Shroud.
• Your eyes turn to pools of darkness and two skeletal, ghostly, flightless wings sprout from your back. The instant you transform, other creatures within 10 ft. of you that can see you must each succeed on a Charisma saving throw (DC 8+ your proficiency bonus + your Charisma modifier) or become frightened of you until the end of your next turn. 
• Your transformation lasts for 1 minute or until you end it as a bonus action, or use a bonus action to revert back to your Radiant Consumption form. During it, once on each of your turns, you can deal extra necrotic damage to one target when you deal damage to it with an attack or a spell. The extra necrotic damage equals your level. 
• Once you use this trait, you can’t use it again until you finish a long rest. You may revert back to your Radiant Consumption form or end your transformation entirely, though you may not switch back and forth. If you revert to your Radiant Consumption form, the initial effects of Radiant Consumption activate as though you were entering it for the first time. 
• You have learned how to use your angelic abilities to your benefit. Once per turn, if you do an attack that deals radiant damage in addition to another damage type (such as a divine smite, or radiant consumption), you can channel the celestial damage into regeneration. Instead of dealing this damage to the target, you can halve the damage, rounded down, and either gain temporary hit points for that amount OR regain sorcery points equal to that amount, up to your maximum amount. You may do this a number of times equal to your proficiency bonus halved (3 times) per long rest.