It is usually used for fast travelling or for running away, because unless he develops it later on, it would be impractical to use in a battle, unless against a opponent who is incredibly weak, more like a group of standard humans than anything else.
Edit: Also, could someone tell me what happens when your character dies? Because I was wondering what happened to them before they could reenter after 3 real time days, or what happens when the tournament is over. Specifically, I was wondering if they were doing something before they reentered, like training, or working on their weapons, or something.