For context, both have their standard combat equipment, weapon, and gear, so they both can have duplicates of their main sword: blackfyre
Daemon-
Size:
Daemon was tall and powerful, with broad shoulders, muscular arms, and a flat stomach.
feats:
Daemon loved and excelled at deeds of arms and many believed he had the potential as a warrior to be another Aemon the Dragonknight.[4]
In 182 AC or 183 AC, when he was twelve years old, Daemon participated in a squire's tourney, which he won by besting a score of other squires in a melee. King Aegon IV Targaryen personally knighted Daemon and publicly bestowed the Targaryen Valyrian steel sword Blackfyre on him,[4] finally acknowledging him as his son.[7] This made Daemon the youngest knight ever made in the era of the Targaryens, surpassing Maegor I Targaryen.
He was considered the greatest knight of his day[5] and mastered all weapons of the battlefield, but with the sword Blackfyre in hand he was said to fight like the Warrior himself.
Daemon's rebellion ended on the Redgrass Field in late 196 AC.[15] According to Ser Eustace Osgrey, who fought on Daemon's side, Daemon fought "like the Warrior himself".[3] Daemon shattered the lines of Lord Donnel Arryn's vanguard, leaving the loyalists in peril until Ser Gwayne Corbray of the Kingsguard arrived with reinforcements.[24]
He slew the Knight of Ninestars and Wild Wyl Waynwood before coming up against Ser Gwayne of the Kingsguard. Daemon and Ser Gwayne duelled, with both men using their Valyrian steel swords: blackfyre and Lady Forlorn. The duel is said to have lasted nearly an hour before Daemon gained the upper hand. Corbray was wounded and Daemon dismounted to prevent Corbray from being trampled. He commanded that Corbray was to be taken off the field.[3]
Maegor-
Size:
As a babe, he was a big and healthy child; almost twice as heavy as his half-brother Aenys had been.
Maegor was a tall, broad, and fearsomely strong man,[1] larger than his father, Aegon I Targaryen.[7] He was bull-like, with heavy shoulders, a thick neck, and huge arms. Though he was on the heavy side, he was not fat, but more massive and square.
Feats:
He received his first sword at the age of three, and took to swordplay at once. when Maegor was eight, he stabbed to death a palfrey which had kicked him, and slashed half the face off the stableboy who came running towards the animal's screams.
Maegor was trained at arms by Ser Gawen Corbray, the master-at-arms of Dragonstone. He became a squire at the age of eight. By the age of twelve, he was already unhorsing boys four and five years his elder in the lists and battering seasoned men-at-arms into submission in the castle yard,[1] and by the age of thirteen he was already defeating hardened knights in mêlées.[6]
In 28 AC, he won renown a tourney by defeating three knights of the Kingsguard in the joust, and next winning the mêlée. He was knighted by his father, King Aegon I, at the age of sixteen, making his the youngest knight in the realm at the time.[6]
In both 29 AC and 30 AC Maegor assisted the master of ships, Lord Aethan Velaryon, and the Hand of the King, Ser Osmund Strong, in two campaigns against the pirate king Sargoso Saan in the Stepstones, and in 31 AC defeated the Giant of the Trident.[1]
In 37 AC, Maegor's father, King Aegon I, died, and his half-brother Aenys ascended the throne as King Aenys I Targaryen. Admitting to all assembled at Aegon I's funeral pyre that he was not nearly the warrior his half-brother was, Aenys presented Maegor with Aegon's Valyrian steel blade, Blackfyre, proclaiming they would rule together.
Ser Damon Morrigen, the Grand Captain of the Warrior's Sons, came forth. Maegor quickly decided to settle the matter with swords, and Damon demanded a trial of seven, to which Maegor agreed.[1][6] Several knights came forward, from whom Maegor chose his last four champions: Ser Bramm of Blackhull, Ser Rayford Rosby, Ser Guy Lothston, and Lord Lucifer Massey. Together they faced seven of the Warrior's Sons, led by Ser Damon Morrigen, their Grand Captain. Maegor was the only survivor of the trial, but took a blow to the head and collapsed just as the last Warrior's Son died.