IEnumerator Spawn()
    {
        while (true)
        {
            if (!distanceController.checkBossStage())
            {
                if (!enemyOnField)
                {
                    enemyOnField = true;
                    yield return(new WaitForSeconds(0.5f));

                    SetEnemyGroup(distanceController.GetStage());
                    rand = Random.Range((0 + stageOffset), (9 + stageOffset));
                    if (enemyGroup[rand] != null)
                    {
                        createdGroup = Instantiate(enemyGroup[rand], transform.position, Quaternion.identity) as GameObject;
                    }
                }

                if (GameObject.FindWithTag("Enemy") == null)
                {
                    Destroy(createdGroup);
                    enemyOnField = false;
                }
            }
            yield return(new WaitForSeconds(0.1f));
        }
    }