Energy Form: After going through the Hex surrounding Westview twice, Rambeau's DNA was rewritten. After going through the barrier a third time, the Hex rewrote her already altered cells, giving Rambeau superhuman abilities. She can transform herself into any form of energy within the electromagnetic spectrum. Among the many energy forms, she has assumed and is able to control are gamma rays, X-rays, ultraviolet radiation, visible light, electricity, infrared radiation, microwaves, and radio waves. She apparently accomplished this transformation by mentally shunting the matter of her body into the dimension from which she draws her energy, and replacing it with a corresponding amount of energy. Her mind remains in the dimension to control the energy-parcel that has taken the place of her body. By assuming an energy-form, she gains all of that energy's properties. Monica is apparently unlimited by the amount of time that she can remain in her energy-form. She can seemingly only transform herself into one wavelength of energy at a time, but she can transform between one energy-state and another in a fraction of a second. As noted above, the limit to the amount of energy she can transmit through her body at a given time is not known. Extensive energy transformation and manipulation can be physically taxing once she returns to her physical form.
Appearance Alteration: Monica can use her facility over light to modulate her energy and modify her appearance, and outwardly take the form of other people. However, when she does so, she doesn't actually change her physical shape nor can she emulate their biometrics.
Immortality: Which much energy stored in her, Monica Rambeau has gained the power of immortality, for which she doesn't age and is immune to diseases, viruses, and cancers.
Flight: Monica Rambeau is capable of flight in any of her wavelengths.
Energy Duplication: When she encounters a new or unfamiliar energy, Monica can often duplicate it given enough time for analysis.
Energy Absorption: Monica gained the ability to absorb energy, which causes her eyes to glow blue when in use. She is capable of absorbing energy given her own energy form is of the right type and at the right wavelength.
Intangibility: Monica Rambeau can also phase through solid matter and certain energy fields depending on their wavelengths.
Invisibility: She is often invisible in most of her forms but can make herself appear visible.
Monica Rambeau on the Marvel Wiki