Wave Spawner does not spawn Next wave?

For some reason, my "Wave Completed Log" doesn't show up. I'm wondering if its because in my player attack Script under Update () I have a get key down that destroys the enemy array DestroyObject (MyEnemies [i]);

I'm unsure if I have to specifically have a Kill enemy() function. Can anyone help me so that way the new wave can be completed and respawned?

Here is the Tutorial I am using https://www.youtube.com/watch?v=q0SBfDFn2Bs&t=691s

public class AttackAnim : MonoBehaviour {

 public GameObject[] MyEnemies;

 //public GameObject[] MyFishes;

 public Animator anim;

 // Use this for initialization
 void Start ()
 {
     anim = GetComponent<Animator> ();
 }
 
 // Update is called once per frame
 void Update ()
 {
     if (Input.GetKeyDown ("w")) {
         MyEnemies = GameObject.FindGameObjectsWithTag ("Enemy");
         //MyFishes = GameObject.FindGameObjectsWithTag ("Fish");

         for (int i = 0; i < MyEnemies.Length; i++)
         DestroyObject (MyEnemies [i]);
         
         //for (int i = 0; i < MyFishes.Length; i++)
         //DestroyObject (MyFishes [i]);
             

         anim.Play ("DaniAttack");
     }
     if (Input.GetKeyDown ("s")) {

         anim.Play ("DaniSheild");
     }

} }

Here is my Wave Script:

public class WaveSpawner : MonoBehaviour { public enum SpawnState {SPAWNING, WAITING, COUNTING};

 [System.Serializable]
 public class Wave
 {
     public string name;
     public Transform enemy;
     public int count;
     public float rate;
 }
 public Wave[] waves;
 private int nextWave = 0;

 public Transform[] SpawnPoints;

 public float timeBetweenWaves = 5f;
 public float waveCountdown;

 private float searchCountdown = 1f;

 private SpawnState state = SpawnState.COUNTING;



 // Use this for initialization
 void Start () {
     waveCountdown = timeBetweenWaves;
     
 }
 
 // Update is called once per frame
 void Update ()
 {

     if (state == SpawnState.WAITING) {
         if (!EnemyIsAlive ()) 
         {
             WaveCompleted ();
         } 
         else 
         {
             return;
         }
     }



     if (waveCountdown <= 0) {
         if (state != SpawnState.SPAWNING) 
         {
             StartCoroutine( SpawnWave (waves[nextWave]));
         }
     } else {
         waveCountdown -= Time.deltaTime; 
     }
 }

 void WaveCompleted()
 {
     Debug.Log ("Wave Completed");
     state = SpawnState.COUNTING;
     waveCountdown = timeBetweenWaves;

     if (nextWave + 1 > waves.Length - 1) 
     {
         nextWave = 0;
         Debug.Log("All Waves Complete! Looping.");
     }

     nextWave++;
 }

 bool EnemyIsAlive()
 {

     searchCountdown -= Time.deltaTime;
     if (searchCountdown <= 0f) {
         searchCountdown = 1f;
         if (GameObject.FindGameObjectsWithTag ("Enemy") == null) {
             return false;
         }
     }
     return true;
 

}

 IEnumerator SpawnWave(Wave _wave)
 {
     Debug.Log("Spawning Wave:" + _wave.name);
     state = SpawnState.SPAWNING;

     for (int i = 0; i < _wave.count; i++) 
     {
         SpawnEnemy (_wave.enemy);
         yield return new WaitForSeconds(1f/_wave.rate);
     }

     state = SpawnState.WAITING;

     yield break;
 }

 void  SpawnEnemy(Transform _enemy)
 {
     Debug.Log ("Spawning Enemy:" + _enemy.name);
     Transform _sp = SpawnPoints [Random.Range (0, SpawnPoints.Length)];
     Instantiate(_enemy, _sp.position, _sp.rotation);


 }

}