Black Crom's Magic

Black Crom's Magic is rare magic that originated from Maeve and Loht, after they created the shadow fey with the Dark Powers. The Dullahan have instinctual connection to Black Crom's Magic.

Macabre Weapon

While holding a weapon you are proficient with, you can use an action to transmute it into human bones fused with fey magic. For example, a whip becomes a spine or a mace becomes a skull. The effect lasts until you end it with an action or are no longer holding the weapon. A macabre weapon deals an extra 2 poison damage.

Innate Spellcasting

Starting at 3rd level, you can cast bane, faerie fire or protection from evil and good. You can do so twice, then must finish a long rest before you can do so again. At 5th level, you can cast find steed or blindness/deafness. You can do so twice, then must finish a long rest before you can do so again. In addition, the extra poison damage dealt by your macabre weapon increases to 3.
Your spellcasting ability is Charisma. Your spell DC is 8 + your Charisma modifier + your proficiency bonus.

The Shadow Fey

Prince Loht is the prince of the shadow fey and indeed leader of all the Unseelie freefolk. Though Loht rules with an iron fist, his Unseelie followers view him with awe and reverence as well as fear. He speaks softly but elegantly, acting in such a fashion as to make his detached brutality the stuff of legends. Under Loht's rule, the Unseelie Court has a decidedly more organised and orderly bent than the Seelie Court. Loht is responsible for more twisted fey creatures, such as face-stealers and headless horsemen.
Loht used to rule a Domain of Dread known as Arak, but when LaFey's rule came to an end, Maeve was able to bring him and the denizens of his domain into the Feywild.