It is highly unlikely that Avatar, even at their most powerful, could defeat Goku.
Goku's Power
- Vastly Superior Power: Goku possesses incredible strength, speed, and energy manipulation abilities, far surpassing anything seen in the Avatar universe. He has trained rigorously for years and has access to powerful transformations like Super Saiyan, which amplify his abilities exponentially.
- Ki Manipulation: Goku's ability to control and manipulate ki, a form of life energy, grants him a wide range of attacks, including powerful energy blasts, telekinesis, and flight.
- Vast Experience: Goku has faced countless powerful opponents throughout his journey, gaining invaluable experience in combat and adapting to different fighting styles.
Avatar's Limitations
- Elemental Bending: While bending elements like water, earth, fire, and air is impressive, it is limited by physical constraints and relies on natural elements.
- Spiritual Connection: Avatar's connection to the Spirit World grants them access to powerful spiritual abilities, but these are primarily defensive and not necessarily offensive.
- Physical Prowess: While Avatar's physical abilities are enhanced by bending, they are not on the same level as Goku's superhuman strength, speed, and durability.
Conclusion
While Avatar's bending and spiritual abilities are impressive, they are ultimately outmatched by Goku's sheer power, experience, and ki manipulation. Goku's ability to destroy entire planets and galaxies with a single attack far surpasses anything Avatar can achieve.