Why did Axel fight Xion in Twilight Town in Kingdom Hearts 358 2 Days?

Answer 1

Axel wants Xion to return to Organization XIII, but she wanted to return to Sora. At the same time, Xion pretty much wantedto be eliminated, because Namine told Xion that if Xion returns to Sora, she'd return Sora's memories so he can reawaken and destroy Organization XIII.

Answer 2

Although there is no way of knowing for sure, it's understandable to assume that Roxas threw the keyblade at Riku because of Xion. Xion could have thrown the keyblade to Riku so that Riku could stop Roxas. Through Roxas, Xion was able to give Riku the keyblade. I know it's very complicated but, hey, that's what Kingdom Hearts is all about.

Another explanation could be that Roxas wanted a challenge from Riku, and to make things fair, he tossed him a weapon, ensuring that Riku would fight Roxas in a fair way. Again, there is no way of knowing exactly why the Keyblade was thrown. These are just a fan's ideas.

Answer 3

To take him to DiZ so that Sora's memories could be restored

Answer 4

Because that was Namine who sent Riku to stop him. Riku had to stop Roxas so Roxas wouldn't get destroyed by the rest of the Organization.