Powers: Graviton can mentally manipulate the particles of gravitational force for which he is named, increasing or decreasing the force of gravity on any person or object, or applying that force in more complex ways for flight, manipulation of objects and force fields. In effect, he is one of the most powerful humans on Earth.
Graviton possesses the ability to mentally manipulate gravitons (that carry the attractive, gravitational force between atomic nuclei), enabling him to control gravity. He can surround any object or person including himself with gravitons and anti-gravitons (particles similar to gravitons but with opposite charge and spin), thus increasing or decreasing the Earth's pull of gravity upon it. By decreasing the pull of gravity beneath him, he can fly at any speed or height at which he can still breathe. By increasing the pull of gravity beneath his opponents, he can pin them to the ground, having made them too heavy to move, or cause sufficient gravitational stress to impair the normal functioning of the human cardiovascular system. He can also cause an inanimate object (such as a 1-foot diameter rock) to radiate enough gravitons to give it its own gravitational field, able to attract nearby matter and energy.
By rapidly projecting gravitons in a cohesive beam, he can generate a force blast with a maximum concussive force equivalent to the primary shockwave of an explosion of 20,000 pounds of TNT. He can also create a gravitational force field around him capable of protecting him from any concussive force up to and including a small nuclear weapon.
Graviton can exert his gravitational control over a maximum distance of 2.36 miles from his body. Thus, the maximum volume of matter he could influence at once is 6.88 cubic miles. He once exercised this control by lifting into the air an inverted conic frustum-shaped land mass whose uppermost area was 4 miles across, and causing it to fly as though it were a dirigible. He can also erect a gravitational force-field of similar proportions. (Graviton can perform as many as four separate tasks simultaneously. (He has not only lifted a 4 mile wide land mass as high as cloud level, but he has also surrounded himself with a force-field, gravitically held most of the Avengers against a slab of rock, and projected force-bolts at Thor all at the same time.) Graviton can use his power at maximum capacity for up to eight hours before mental fatigue significantly impairs his performance, and considerably longer (up to eighteen hours) if he conserves his energy during that
I add to this, that:
During his 2nd encounter with the Thunderbolts, he lift an enormous piece of land and keep flying in the sky, claming it was hiw own realm, the "Sky Island", and the same time, he grant hundred of people to fly, and fight with the Thunderbolts wiping them out with ease.
During his 3rd encounter with the Thunderbolts, he was going to manipulate the surface of the continents and give them the shape of his face, read with attention, manipulate the continents.He also prevent the arrive of all the super heroes through holding them up into the sky and rending them unconscious with his control over gravity.He was finally beaten from the T-Bolts cause he give them the chance to get near him.Just cause he underrate his enemies.
All this just to say, Graviton is powerful than Magneto, and he can win this match fast and easy.