Holly and Ash are twin brothers, the result of a rape during the last goblin-sidhe war. One parent was Seelie the other a goblin.
They look quite sidhe with blonde hair, lithe bodies, and sun kissed skin - rare among the Seelie, unheard of among the Unseelie, but their eyes are wholly goblin. Holly's eyes are the pure red of holly berries in winter, while Ash's are solid summer grass green with no whites showing.
King Kurag introduced them as twins left on his doorstep, but now feared among goblins - the highest praise for a goblin warrior.
The brothers do all things together. They never disagreed until it came to the question of going to Princess Meredith's bed in hopes of manifesting sidhe powers. Ash was for it, Holly opposed: "We are goblin, and that is better." Ash, however, knew that goblins once had magic of their own, and wanted a return of it, and as the dominant twin, he got his way. Holly followed his brother as he always had, and always would.
During the battle outside the sithen Merry's magic called to the Red Caps and it called to the twins, suggesting that their father may have been a Red Cap. They showed up hating that her hand of blood called to them. When she asked if they wanted to be sidhe Holly said no and Ash said yes. She promised them power and they took her hands, transporting to the place of vision she had gone before to encounter the goddess and consort.
After the encounter with the deities, they were left completely alone, the only situation in which they could admit that they like the gentle aspects of their natures as well as the goblin. "We are goblins, but we are also ourselves." Holly admitted to being a little more goblin than his brother. After Merry took the twins as lovers, they each emerged with a sidhe hand of power mirroring Merry's; the hand of blood for Holly, and the hand of flesh for Ash.