Joann wins. Highlights:

• Joann's Overwhelming Strength: Joann's ability to casually carry an island the size of Wano dwarfs even Goku's considerable power. The sheer scale of his strength makes any direct confrontation incredibly one-sided. A single punch from Joann would likely obliterate Goku.

• Speed Advantage: Joann's speed exceeding light ensures he can consistently land blows before Goku can react. Goku's speed is impressive, but it's not on the same level as exceeding the speed of light. This speed advantage is crucial in negating any potential counterattacks from Goku.

• Teleportation Tactic: Joann's teleportation ability allows him to bypass Goku's defenses and deliver devastating blows from unexpected angles. This strategic advantage prevents Goku from utilizing his ki blasts or martial arts effectively. Goku would be constantly caught off guard.

• Goku's Limitations: While Goku possesses immense power and fighting skills, his abilities are ultimately limited by the physics of his universe. He has never faced an opponent with Joann's level of raw, uncontainable strength and speed. His ki blasts, while powerful, would likely be insignificant against Joann's durability and ability to withstand such attacks. Even his Kaio-ken technique would be insufficient to bridge the gap in power.

• The Decisive Blow: The fight would likely end quickly. A single, well-placed punch from Joann, delivered via teleportation, would be enough to instantly incapacitate or kill Goku. The sheer force behind the blow, amplified by Joann's strength, would be insurmountable. There's no realistic scenario where Goku could win this fight.