John Stewart

Powers

The Ring is the greatest weapon in the universe, and thus there is no limit to what it can do, but here are some abilities it has been shown to have.

Animating:

A Green Lantern can will things to move how he wants and control them.

Illusions

A green lantern can create illusions to fool or frighten their enemies.

Artificial Intelligence:

Every ring has a connection to the Main Battery on Oa, which taps into an artificial intelligence. It acts as an "on-board computer," telling the wearer what they need to know and info about villains. It can either respond out loud, or silently directly to the wearer's mind. The AI contains a large database of information that may be crucial to a Lantern's success. The ring also translates nearly every language to and from the wearer, which is why the Corps can communicate with each other. When the bearer of a Green Lantern ring dies, the ring will seek out a suitable replacement for their sector.

Burglar Alarm:

A Green Lantern can coat anything with the ring's beam and thus, if anyone other than himself touches it, his ring will glow, alerting him to the possible theft.

Communicator:

The ring can act as a personal communicator between Green Lanterns. They have also been seen connected to telephones.

Costumes:

The wearer of the ring may create any costume they choose, based on their personal preferences, whenever they choose. The ring projects the costume over any clothes already worn at the time.

Energy Beams, Bubbles, Force-Fields, and Blasts:

The rings can also project beams, form protective bubbles and force fields, and fire destructive blasts. Sometimes, depending on the wearer, the beams and blasts make sounds. The ring has been able to contain a supernova

Energy Constructs:

The rings can construct anything the wearer can imagine from hard-light energy, as long as they are willing to make it. The more determined the wearer is, the more complex and intricate these things can be. The constructs can even be so complex as to form working machines, computers, and even people.

Flight:

The ring allows the wearer to fly in atmosphere or in space, and can achieve light-speed, moving from planet to planet in a matter of hours.

Invisibility:

The ring can make the wearer or anything else invisible but aliens have been able to cast a shadow or grope the air to find the thing.

Matter Manipulation:

A Green Lantern can use their ring to manipulate nearby matter, such as water, for various purposes such as a construct that acts like an energy construct but can block something yellow and may serve a purpose that an energy construct couldn't perform. Also, they can convert matter to other forms such as changing bullets to water.

Mind Control:

The wearer of the Ring can use it to plant post hypnotic commands or control a person to do his bidding.

Phasing:

The ring allows the user to go through walls.

Power Absorbing:

In the JLA's first fight with Amazo, it was GL who defeated him by drawing out all of Amazo's powers. In Green Lantern/Silver Surfer: Unholy Alliances, Kyle defeated Parallax with SS' power and Thanos with Oa's energy by drawing out all that extra energy from them which made them unconscious. However he couldn't hold all that power nor could his Ring like Hal did with Amazo's powers, so that move isn't often used with so much power.

Probing:

The ring can probe the Lantern's or another person's mind, allowing him to uncover memories or the person's thoughts.

Radiation

Besides light based radiation used to create the energy constructs associated with a Green Lantern, the ring can simulate various forms of radiation. One example of this is the ability to simulate the radiation of Green Kryptonite, a form of radiation that is harmful to Superman.

Recharging

The rings need to be recharged by means of a Power Battery. Other large sources of power may be used to recharge a power ring, however effectiveness may vary. The internal power source of a Manhunter Android is, in effect, the same as a power battery, and can be used to recharge a power ring. During the JLA / Avengers crossover, a Cosmic Cube was used to recharge a depleted ring, although this is not an ideal solution and is available if there are no other options.

Ring Duplication:

Each ring can duplicate itself, creating a second ring which may be given to another as a backup, for protection, or to help the lantern in times of great need. This duplicate ring must is exactly like a normal ring.

Temperature Control:

The Ring can increase or decrease the temperature of anything, even something as large as stars, or even create bubbles of intense heat or cold, even down to Absolute Zero.

Transforming:

The ring can transform anyone or anything, be it into an animal, altering their state of appearance, or their size. Once Hal and Alan turned the two Flashes (Bary and Jay) to light protons in order to free them from prisons.The green lanterns can shrink a person to a very small size,unseen by human eyes.

X-Ray:

The ring can allow the user to see through walls, without the people on the other side knowing.