Is Axel a good or bad guy?

Answer 1

It depends on who's talking.

To Roxas, Axel is a good guy, as one of his two friends in Organization XIII. He helped him on missions, and the two of them were very close.

To Sora, Donald, and Goofy, Axel is neither good nor evil. Sora doesn't understand Axel's intentions, but Axel helps him out during the battle at Betwixt and Between.

To everyone else, Axel is a bad guy. He's a member of Organization XIII, and the Organization has dubious intentions.

In the course of every game, though, it's fairly safe to say that, even though you can't really call him a hero, Axel is not a bad guy.