Prefight.cs

using UnityEngine;
using System.Collections;
using UnityEngine.SceneManagement;

public class Prefight : MonoBehaviour {

	public int time;

	// Use this for initialization
	void Start () {
	}
	
	// Update is called once per frame
	void Update () {
		if (time > 0) {
			time--;
		}
		else {
			SceneManager.LoadScene("arena");
		}
	}
}