Each Green Lantern wields a power ring that can generate a variety of effects, sustained purely by the ring wearer's imagination and strength of will. The greater the user's willpower, the more effective the ring. The upper limits of the power ring's abilities are not clearly defined and it has been referred to as "the most powerful weapon in the universe" on more than one occasion. It has also been stated that every weapon has a weakness and the weakness a Green Lantern ring has is its wearer (though some argue that this is its strength). Across the years, the rings have been shown capable of accomplishing almost anything within the imagination of the ring bearer. Stories in 2006 nicely retconned the ring's long-established ineffectiveness on yellow objects, stating that the ring-wielder need only feel fear, understand it and overcome it in order to affect yellow objects (however, it is a learned and practiced ability, making it a weakness to some Green Lanterns), giving retroactive credence to the explanation of the ring's real but surmountable weakness to yellow.
Power rings as used by various wielders have exhibited (but are not limited to) the following effects:
* Constructs of green 'solid-energy,' which can vary from microscopic to tremendous in size and/or complexity and are limited ONLY by the imagination.
* Flight, including flight at speeds beyond that of light, although this does create an enormous expenditure of energy; users tend to rely on using wormholes for long distance travel.
* Relatively instantaneous transport across the galaxy and to other galaxies through generated wormholes
* Destructive plasma bolts
* Energy force beams that can be used to capture, hold and manipulate solid objects
* The rings can act as semi-sentient computers and accesses information through its connection with the Book of Oa. The rings have problem-solving skills but they cannot make decisions or take actions on their own, and must be given directives by the wearer.
* Time travel (One solitary power ring cannot generate enough power for time travel; several power rings are needed to complete this feat.)
* Telepathy
* Translation of nearly all languages
* Force field generation, a protective aura used to shield the wearer from the rigors of the vacuum of space. Strength and durability of force field in combat is limited by the user's will power. Contrary to some canon, a Green Lantern ring currently does not automatically protect its wearer from harm but must be willed into existence.
* Creation and emission of certain types of Radiation, including simulated kryptonite radiation.
* Generation of mental "earplugs" to block out telepathic communication and manipulation.
* Rendering user invisible.
* Allowing wearer to phase through solid objects
* Placing humans into a state of suspended animation
* Accelerated healing of wounds, protection and treatment from viruses and biological attacks and certain surgical procedures including reattachment of severed limbs and digits. More advanced medical procedures must be performed manually and are limited by the wearer's knowledge of medicine.
* Size manipulation allowing ring bearers to grow or shrink in size, the extent of which has not been explored.
* In Green Lantern: First Flight Sinestro was able to "reconnect synapses" in the brain of a dead criminal in order to extract information via a kind of guided discussion.
* Teleportation (an ability that has not been used in quite some time and may be outside the ability of modern Green Lanterns)
* Virtual shape-shifting by generating a hard-lined holographic disguise around the ring bearer.
* "Digitizing" the wearer to absorb them into the ring where they can live in a wearer-generated "world" of their own nearly indefinitely.
* Diagnostic capabilities
http://en.wikipedia.org/wiki/Green_Lantern#Powers_and_abilitiesVulcan is a mutant with the ability to psionically manipulate vast amounts of energy. In addition to traditional energies of the electromagnetic spectrum Vulcan has displayed control over exotic energies such as Cyclops' optic blasts and magical energy.
He has used his powers to produce light, heat, force, and electricity, as well as warp or disable large amounts, and different types, of existing energy sources, tap into and suppress mutant energies, survive in the vacuum of space, and fly. Outside a planetary atmosphere his flight speed can even reach near the speed of light. He is able to go without food for long periods by directly absorbing energy. He can manipulate electricity within a person's brain. He can also use the powers of others by manipulating the energy in their brain. When he uses his powers, his eyes glow. He has been confirmed as an Omega-level mutant in Uncanny X-Men #483, his powers elevated to said level thanks to absorbing a massive amount of mutant energies from M-Day, as stated in Uncanny X-Men #477.
Vulcan is able to use his psionic abilities for a variety of uses. Despite little (if any) formal training in the use of his mental powers, Vulcan has demonstrated feats such as completely resisting mental manipulation/assault by far more experienced telepathic beings, and he was also able to restore former Shiar emperor D'Ken from a catatonic state, something the most powerful/skilled telepaths of the entire Shiar empire had previously been unable to accomplish. Vulcan does NOT possess any innate telepathic abilities, but can manipulate the telepathic energies of other (which enables him to shield his mind from outside attacks). In the instance with D'Ken, he used his energy powers to reactivate portions of D'ken's mind that had been damaged by the M'Krann Crystal.
After being swallowed by the soil of Krakoa, he absorbed the powers of his teammates Sway, Darwin, Petra, and giving him their powers of time manipulation, physical adaptation, and earth manipulation respectively. He has not displayed these abilities after his re-appearance.
All three Summers brothers have similar powers, as they are each able to absorb certain kinds of celestial energies and re-channel that energy from their bodies. While his brothers Alex and Scott are known to be immune to each others powers, they are apparently not immune to Vulcan's.
When not in possession of Darwin's powers, Vulcan's body is as vulnerable as any normal human as far as durability is concerned. However, Vulcan can use his energy abilities to rebuild damaged/destroyed portions of his body.
http://en.wikipedia.org/wiki/Vulcan_%28Marvel_Comics%29#Powers_and_abilities