[Note: The following continues GRRM's series of descriptions of notable Targaryens (and Targaryen bastards) for Amoka. Added to it is a correction related to the arms of Bittersteel, which GRRM had changed since his original conception.]
BLOODRAVEN
Bloodraven first, since I've already described him in "The Sworn Sword." The natural son of King Aegon IV by his sixth mistress, Lady Mylessa ('Missy') Blackwood, Brynden Rivers is an albino, with milk white skin and white hair, worn long. His eye is red -- the one he still has, the right. At the Battle of the Redgrass Field, his left eye was put out by Bittersteel when they dueled. He seldom wears an eye patch, but prefers to display his scar and empty socket to the world.
On the right side of his face, over his throat and extending up to his cheek, he has the red winestain birthmark from which he gets his name. The birth mark is said to look somewhat like a raven drawn in blood. However, the likeness is hardly exact. Dunk thinks the birthmark just a splotch. It is more a suggestion of a raven shape, like a Rorschach ink blot.
His colors are "scarlet and smoke," smoke being a sort of dark grey streaked and mottled with black. Because his skin is very senstive to the rays of the sun, he frequently goes about cloaked and hooded.
His sigil is a white dragon (one-headed) with red eyes. (Elio has a version of it, I believe). He is a shade under six feet tall and very thin, gaunt, with a grim unforbidding aspect and a sinister reputation as a sorcerer and spymaster. Although he bears the Valyrian blade Dark Sister than once belonged to Aegon's Visenya, his favorite weapon is a tall bone-white weirwood longbow. He is an expert bowman. His longbow is weirwood, and should be white.
DAEMON BLACKFYRE.
The first and greatest of the Blackfyre Pretenders was the natural son of Daena Targaryen, sister, betrothed, and (briefly) wife to King Baelor the Blessed. Baelor never consummated the marriage, and had it dissolved when he ascended the Iron Throne. Daena and her two sisters were thereafter kept in a comfortable confinement in the Red Keep, in what became known as the Maidenvault. Despite her guards, however, Daena became pregnant and give birth to a strong, healthy son, Daemon. She refused to divulge the name of his father, and thereby became known as "Daena the Defiant." It was not until many years later, when the boy was a squire and bested a score of other squires in a tournament melee, that King Aegon IV (Princess Daena's cousin) acknowledged him as his own, and presented him with Blackfyre, the Valyrian steel blade of Aegon the Conquerer and all the Targaryen kings thereafter.
Targaryen on both side, Daemon had all the hallmarks of his house; the silver-gold hair, the deep purple eyes, fine features of almost inhuman beauty. Daemon's friends and supporters often remarked on how much he resembled Aegon the Conquerer (or at least his likeness, since none of them had ever seen Aegon in the flesh), and indeed there was a certain similarlity, though Daemon wore his hair long, flowing down to his shoulders in a silvery-gold mane. He went clean-shaved, with neither beard nor mustache. Daemon looks every inch the warrior; broad shoulders, big arms, a flat stomach, but he was also a man of considerable charm. I'd give him a warm smile. He made friends easily, and women were drawn to him as well.
As a bastard, Daemon Blackfyre bore the arms of House Targaryen with the colors reversed: a black three-headed dragon on a red field. Thus he became known as "the Black Dragon." His armor would be ornate and costly, all black and red plate, and his warhelm was distinctive, with batlike steel "dragon wings" on the sides.
BITTERSTEEL
His real name was Aegor Rivers, and he was the natural son of King Aegon IV by his fifth mistress, Lady Barba Bracken. Younger than Daemon Blackfyre, older than Bloodraven. Bittersteel was also a warrior, and looked the part. He was only half Tagaryen, so he got the purple eyes, but his hair was black. As a adult he wore a beard, cropped very short, little more than a shadow on his face and jaws. Somewhat of a Conanesque look to him, but not the Frank Frazetta Conan and definitely not the Arnold Conan, more the Barry Windsor-Smith version, or the one described by REH -- he is tall and well made, but lean and lithe as a panther. And angry. No smiles here. Bittersteel was pissed off all his life, and had a special loathing for Bloodraven and his mother, who had displayed his own mother as the king's favorite.
His armor is well-made but plain, no nonsense grey-steel and black rings. His helm bears a horsehead crest with a horse's mane flowing down behind. His shield has a grey longsword displayed bendy sinister, witha a black dragon's head above and a red horse's head below, both facing out. The field is white.
If you are going to include the Great Bastards in a group shot, Daemon and Bittersteel should both be taller and more imposing than Bloodraven, the scrawny one of the lot.
....Don't bother working up those arms for Bittersteel, I've already changed them. Came up with a much cooler image...
So here's Bittersteel: a winged red stallion on a golden field. Only the horse has big black dragon wings instead of the usual Pegasus-style feathered angel wings, and he's snorting fire.