Akumatenshi (Artwork by yuyo and うさの on pixiv)

Magic Detection. Akumatenshi are innately aware of magic in the area (30 feet). They must take an action to discern what magic it is.  If they are completely surrounded by magic and more than 15 cubic feet of the area is covered, they cannot discern any of the magic around them, and trying to do so knocks you out.

Limited Flight. Akumatenshi can fly, but their wings quickly get exhausted. An Akumatenshi can fly for (2d6 x dex modifier x (# of wings / 2)). Gliding for 4 minutes regains this flight time.

[Magic Nullification. weak resistance (25% reduction) against magical damage and 15% damage reduction against spell attacks. (Upgraded with higher Magic Nullification levels)

Magical Prowess. Grants advantage on spellcasting. Nullified if spellcasting disadvantage is applied.

Magic Discernation (continuation of Magic Detection). Akumatenshi must take an action to discern what magic they are detecting and they must take a number of minutes equal to the spell’s level times two to study it. 

Magic transcription. Akumatenshi can copy spells that they have studied. They can transcribe that magic as a rune onto an object, allowing them to cast that spell once per rune without needing the required materials or casting time. Runes refill with magic after a long rest.

Magic Combination. Akumatenshi can combine runes and already known spells to create powerful spell combinations called mahoujin. A combined spell can be memorized, which takes 1 minute per spell applied, or transcribed. Combined spells project one or more magic circles with the runes used when activated.

Claw Attack. Melee Weapon Attack., reach 2 feet., damage 1d4 slashing.

Headbutt. Melee Weapon Attack., reach 2 feet., damage 1d4 piercing x # of horns.

Akumatenshi can attempt dodge, counter, react by casting or activating a spell or block an an attack or event that they can see coming as a reaction.