During the Uranian Eternals' destruction, they rushed to completion a duplicate of Marvel Boy. The duplicate arose too late to be of any help, however - it was born an unstable creature with false and fractured memories. It believed that the Eternals' protective dome was destroyed, and it was the fault of bankers of Earth who stalled him when they denied his request for a loan to purchase medical supplies for his father. He rushed back to Earth to exact revenge, calling himself The Crusader, and he began a rampage. Armed with was later found to be the "Quantum Bands", he faced the Fantastic Four. When he lashed out in rage and nearly defeated them, but in his madness the bands found him to be unworthy and disintegrated the him, leaving just the Quantum Bands behind. These would be retrieved by Reed Richards, given to SHIELD, and passed down to Wendell Vaughn, the hero would take the name Marvel Boy and then Quasar.
Thelius was recreated (along with three former bearers of the Quantum Bands) by Thanos to destroy Quasar at the funeral of one of his oldest enemies, Eon. Thanos promised the "Quantum Banders" that the last one of them standing after they killed Quasar would be Thanos' Protector of the Universe for all time. After a fiece struggle, Quasar managed to destroy the other members of the Quantum Banders within the Quantum-Zone and left Thelius alive but trapped within the Eonverse.
Later, Thanos contacted Thelius and freed him from the Eonverse after Quasar had died and named Thelius his new protector. Thelius attempted to co-opt Quasar life on Earth even going so far to try to "team-up" with the Punisher and to join the Avengers. After Quasar managed to resurrect himself (with the help of the Starbrand), he trapped Thelius within the White Room.
Thelius wielded the Quantum-Bands for decades until he died abusing their power against the Fantastic Four. When he was later resurrected by an Infinity Gauntlet empowered Thanos, he created a set of perfect replicas of the Quantum-bands for Thelius and the other Quantum-Banders.
Primarily, the bands are tools for manipulating forms of energy. A bearer of the quantum-bands can affect, alter, absorb, and channel any form of energy found in the Electromagnetic spectrum, from Gamma Rays to Radio Waves, and this also includes visible light.
- Energy Constructs: The bands can construct anything the wearer can imagine from "Quantum energy", This energy is derived from the Quantum-Zone, although the bands can absorb energy from all known sources.
- Flight: The bands allow the bearer to fly in atmosphere or in space (surrounding the wearer in an energy aura to protect from air-friction or the vacuum of space), and can achieve incredible speeds (Wendell Vaughn once flew from New York Harbor to the Sea of Tranquility in under 5 minutes). Quasar was often clocked at near light-speed. Starhawk was estimated at traveling at "thrice light-speed" by Era, Eon's child in an alternate future.
- Teleportation: they also enable the bearer to quantum jump or create apertures between the fabric of space/time of various sizes. Allowing the wearer access to the realm of potential energy which the bands interface with known as the Quantum-Zone. A wearer can then travel through this trackless, featureless zone and emerge at a different point in our physical space light years away from his starting point only seconds later. His Quantum-bands would enable him to keep his bearings while in the zone and thus emerge where he wants to. He can cross countless light years in a single jump (Quasar regularly traveled from our star system to systems in other galaxies) if he so desires. Important note, however, she cannot quantum-jump within an atmosphere without ripping a hole in its ozone layer.
- Communications: The bands can detect, emit, and receive radio waves; thereby the bearer can communicate with other radio receivers. The bands can also create a “Quantum-link” which appears as a glowing golden sphere about 2 inches in diameter, which travels to the point of contact at warp speeds and connects with any communication device present allowing the bearer to carry on near-instantaneous communications even over extra-galactic distances.
- Altered metabolism: One previous bearer of the Quantum bands ( Marvel Boy) has been known to be able to augment his strength and stamina to unknown limits with the Quantum-bands. William Wesley was shown to be able to lift an automobile when he was field testing the "Power-bands". Quasar himself rarely exhibited this ability and only when it was needed. He once physically restrained She-Hulk by himself, whether this was a statement of his augmented physical strength or her own restraint is unknown, though she seemed to struggle against him.
- Mental protection: Despite the fact that the Quantum-Bands have no control over the mind or Psionics, at least one previous bearer (Quasar) had "programed" the Bands to protect his mind for mental attacks and takeover. So powerful is this protection that powerful psychics, such as Moondragon or the Overmindcould not overcome it.
- Mental/Physical bond: The Quantum Bands bond with their bearer upon contact interfacing the bearer's mind with the Bands allowing for mental control. Permanently affixing themselves generally to the bearer's wrists, the flesh and bone within rendered indestructible so long as the bond with the bands persists. The bond can only be broken upon the bearer's death, at which point the bands could be removed easily.
- Worthiness: Similar to the hammer of Thor ( Mjolnir), a bearer of the Quantum-Bands must to be worthy. As the Quantum-Bands are tied to the station of the Protector of the Universe, the bands seem to require a calm mind lacking ‘killer instinct’ to learn to use them to their fullest potential. A bearer with the intent to commit acts of depravity and destruction will quickly find himself losing control of the energy output of the bands until they disintegrate him.
- Magic: The Bands cannot absorb it or resist it. However, an enchanted physical object will only be as strong as the object itself would otherwise be. Therefore, Thor's hammer (Mjolnir) will simply not shatter Quasar's forcefield like glass. Fortunately, magicians have no control over the energies he manipulates so, it evens out.
- Extradimensional energy: Quasar is susceptible to all persons using Darkforce. The Q-bands cannot create constructs to hold or resist darkforce energy. The Darkforce penetrates his energy like it wasn't even there. Also entities from the Negative-Zone (such as Annihilus) can corrupt the bands if wearing them.
- Kinetic energy: The Quantum Bands have no defense against someone manipulating it psionically. (Which is why Maelstrom overwhelmed Quasar so easily to begin with), but a bearer can resist a kinetically imbued object (such as a knife or a deck of cards) If a bearer of the Quantum Bands senses the attack they can throw up a shield to defend themselves with.
- Psionic energy: A psionic blast will cut through any quantum constructs like paper mache'. Fortunately, most psionic manipulators are susceptible to the energies of the Quantum-Bands, so it evens out.
- Matter manipulation: Foes who manipulate matter, psionically or otherwise, the Quantum Bands cannot effect their powers. They deal with energy, not matter. The Molecule Man, Sersi, Phoenix, Her, and theSilver Surfer, among others, affect matter in a way that a bearer of the Q-bands cannot. However, Her, Sersi, and the Silver Surfer use cosmic energy to power their matter manipulation abilities and therefore a practiced bearer could affect the energy source, but not the ability itself.