Destiny is a personification of The Endless
who is usually manifest as a man in a dark brown monk-like robe carrying a large book which is chained to his wrist. His hood is always covering his face, leaving it in darkness irregardless of the light sources in the room. He does not so much walk as he does move
about seemingly effortlessly. His book is the book that tells the story of everything that has ever happened and will ever happen and as he reads it the words on the page reveal themselves as things transpire. The pages that have yet to appear would be blank if anyone else turned to them. His realm is one of an endless maze that contains many forks in the road and many choices to make.
There is a lot about Destiny, eldest brother of The Endless that his siblings do not know. They believe him to be a very slow and methodical no-nonsense kind of guy who never changes, because that is how he has been since before any of them were born. In fact he chooses to uphold this facade for their benefit. In actuality, over the centuries he has automated much of his workload and delegated many responsibilities to others that he trusts implicitly. The chain to his book is wired to a remote that broadcasts destiny as it happens to a place in his realm called The Impending. There it's channelled through several sophisticated computer systems, analyzed and recorded --with backups-- for him to examine or refer to at his leisure. There's a team of individuals who keep The Impending running for Destiny, so he can go about and relax and enjoy his long life as an immortal being who can die.
Among Destiny's many talents, he can change his appearance at will. In fact, all the Endless can do this, but Destiny's the oldest so he's been at it longer. Since his siblings have never seen his face, he does this practically right under their noses sometimes. His most common appearance in modern times is a man in a finely tailored conservative suit wearing sunglasses with slicked back hair and conservative but stylish shoes. No tie. No buttons on the white collared shirt. He has a much more ironic sense of humor than most people realize. Destiny has a polite relationship with his sister Death whom he envies for her ability to just come out and be herself, and a strained but tolerant understanding with Desire who is largely the reason why he won't just come out and be himself. His youngest sister Delirium knows something that is not in his book and he tries not to let that bug him. On his appointment calendar, he has a customary routine acknowledgement of Despair and visits her when it is required, but he dreads these visits because she simply irks the begeezus out of him. Destiny has a general tendency to ignore or disdain Dream completely, depending on his mood. Destiny keeps his distance from each of them as best as he can, despising what he has to be when he is around them; this outdated facade and a symbol to them that things never change. Still, he didn't leave his job like Destruction did. At least he keeps his appointments and responsibilities, unlike some people.
And here you thought he was just a stick in the mud, didn't you? Neil Gaiman wrote The Sandman series of comic books which told the story of his brother Morpheus, but Destiny only played a small role in that storytelling. Destiny's story is much more interesting. Too bad no one will ever get a chance to uncover it.