"You told me your sons died fighting for the king."

"And so they did. The rightful king, Daemon Blackfyre. The King Who Bore the Sword. -The Sworn Sword

Daemon Blackfyre: The King who Bore the Sword

Is anyone else in the series described as majestically as as Daemon Blackfyre? I think its obvious GRRM was trying to make the alternative to Daeron II as opposite as possible, but my goodness the dude seems like a straight up legend:

GRRM compares him to Thor

Daemon was very much a Targaryen, albeit bastard born. He had the silver-gold hair, the purple eyes. He looked heroic; tall, muscular, handsome, wide shoulders, flat stomach. A great warrior. Clean-shaven, wears his hair long, like Marvel's Thor. Can be charming and charismatic too, with a winning smile. He used the arms of House Targaryen on his battle standards, but with the colors reversed: a black three-headed dragon on a red field. He'd bear the same sigil on his shield. I can imagine him in gorgeous, ornate plate armor, red and black, black dragon wings sprouting from his helm. -SSM, Concerning the Great Bastards: 6 April 2004

Half a god among mortal men

Valyrians/Targaryens for the most part are described as almost demigods, but I have yet to see one described quite like Daemon:

Yet too many men looked upon Baelor's dark hair and eyes and muttered that he was more Martell than Targaryen, even though he proved a man who could win respect with ease and was as open-handed and just as his father. Knights and lords of the Dornish Marches came to mistrust Daeron, and Baelor as well, and began to look more and more to the old days, when Dornishmen were the enemy to fight, not rivals for the king's attention or largesse. And then they would look at Daemon Blackfyre—grown tall and powerful, half a god among mortal men, and with the Conqueror's sword in his possession—and wonder. -TWOIAF, The Targaryen Kings: Daeron II

The Redgrass Field

Daemon was the Warrior himself that day. No man could stand before him. He broke Lord Arryn's van to pieces and slew the Knight of Ninestars and Wild Wyl Waynwood before coming up against Ser Gwayne Corbray of the Kingsguard. For near an hour they danced together on their horses, wheeling and circling and slashing as men died all around them. It's said that whenever Blackfyre and Lady Forlorn clashed, you could hear the sound for a league around. It was half a song and half a scream, they say. But when at last the Lady faltered, Blackfyre clove through Ser Gwayne's helm and left him blind and bleeding. Daemon dismounted to see that his fallen foe was not trampled, and commanded Redtusk to carry him back to the maesters in the rear.

If it wasn't for his compassion, the Blackfyre story is completely different:

And there was his mortal error, for the Raven's Teeth had gained the top of Weeping Ridge, and Bloodraven saw his half brother's royal standard three hundred yards away, and Daemon and his sons beneath it. He slew Aegon first, the elder of the twins, for he knew that Daemon would never leave the boy whilst warmth lingered in his body, though white shafts fell like rain.

Required Sorcery/Aid of deities to kill him

I'm being a bit hyperbolic here, but it fits with the post:

Nor did he, though seven arrows pierced him, driven as much by sorcery as by Bloodraven's bow. Young Aemon took up Blackfyre when the blade slipped from his dying father's fingers, so Bloodraven slew him, too, the younger of the twins. Thus perished the black dragon and his sons. -The Sworn Sword

Daemon's Skill

Sure, Sure Eustace might be a little biased but still:

"Daeron . . ." Ser Eustace almost slurred the word, and Dunk realized he was half drunk. "Daeron was spindly and round of shoulder, with a little belly that wobbled when he walked. Daemon stood straight and proud, and his stomach was flat and hard as an oaken shield. And he could fight . With ax or lance or flail, he was as good as any knight I ever saw, but with the sword he was the Warrior himself. When Prince Daemon had Blackfyre in his hand, there was not a man to equal him . . . not Ulrick Dayne with Dawn, no, nor even the Dragonknight with Dark Sister.

"Daemon, though . . . Daemon was no more pious than a king need be, and all the great knights of the realm gathered to him. It would suit Lord Bloodraven if their names were all forgotten, so he has forbidden us to sing of them, but I remember. Robb Reyne, Gareth the Grey, Ser Aubrey Ambrose, Lord Gormon Peake, Black Byren Flowers, Redtusk, Fireball . . . Bittersteel! I ask you, has there ever been such a noble company, such a roll of heroes?

You ask me why? Because Daemon was the better man. The old king saw it, too. He gave the sword to Daemon. Blackfyre, the sword of Aegon the Conquerer, the blade that every Targaryen king had wielded since the Conquest . . . he put that sword in Daemon's hand the day he knighted him, a boy of twelve." -The Sworn Sword

As a child

Daemon was the name Daena gave to this child, for Prince Daemon had been the wonder and the terror of his age, and in later days that was seen as a warning of what the boy would become. Daemon Waters was his full name when he was born in 170 AC. At that time, Daena refused to name the father, but even then Aegon's involvement was suspected. Raised at the Red Keep, this handsome youth was given the instruction of the wisest maesters and the best masters-at-arms at court, including Ser Quentyn Ball, the fiery knight called Fireball. He loved nothing better than deeds of arms and excelled at them, and many saw in him a warrior who would one day be another Dragonknight. King Aegon knighted Daemon in his twelfth year when he won a squires' tourney (thereby making him the youngest knight ever made in the time of the Targaryens, surpassing Maegor I) and shocked his court, kin, and council by bestowing upon him the sword of Aegon the Conqueror, Blackfyre, as well as lands and other honors. Daemon took the name Blackfyre thereafter. -TWOIAF: The Targaryen Kings: Aegon IV

TLDR: In order to create a complete opposite of Daeron II and counter the Blackfyres to the Targaryens, GRRM made Daemon Targaryen a demigod.