Aoe (Area of effect) only hits one at a time instead of all that have been hit

Hello Everyone, I tried to create a "field of damage" with a Physics.OverlapBox. Tracking of multiple colliders is possible with my code and i can do damage at these. But only one at a time. If one died, the next target gets damaged but i want that all targets within the Physics.OverlapBox gets damaged at the same time.

 [RequireComponent(typeof(CharacterStats))]
 public class PlayerCombat : MonoBehaviour
 {
     bool m_Started;
     public LayerMask m_LayerMask;
     public GameObject Cube;
 
     public float attackSpeed = 1f;
     private float attackCooldown = 0f;
 
     public float attackDelay = .6f;
 
     public event System.Action OnAttack;
 
     CharacterStats myStats;
                     
 
     private void Start()
     {
         myStats = GetComponent<CharacterStats>();
         m_Started = true;
     }
 
     private void Update()
     {
         attackCooldown -= Time.deltaTime;
     }
 
     public void Attack(CharacterStats targetStats)
     {
         if (attackCooldown <= 0f)
         {
             StartCoroutine(DoDamage(targetStats, attackDelay));
 
             if (OnAttack != null)
             {
                 OnAttack();
             }
             attackCooldown = 1f / attackSpeed;
         }
     }
 
     IEnumerator DoDamage(CharacterStats stats, float delay)
     {
         //Use the OverlapBox to detect if there are any other colliders within this box area.
         //Use the GameObject's centre, half the size (as a radius) and rotation. This creates an invisible box around your GameObject.
         Collider[] hitColliders = Physics.OverlapBox(Cube.transform.position, Cube.transform.localScale / 2, Quaternion.identity, m_LayerMask);
         int i = 0;
         //Check when there is a new collider coming into contact with the box
         while (i < hitColliders.Length)
         {
             //Output all of the collider names
             Debug.Log("Hit : " + hitColliders[i].name + i);
             //Increase the number of Colliders in the array
             i++;
 
             yield return new WaitForSeconds(0);
             stats.TakeDamage(myStats.damage.GetValue());
         }
     }
 
     void OnDrawGizmos()
     {
         Gizmos.color = Color.red;
         //Check that it is being run in Play Mode, so it doesn't try to draw this in Editor mode
         if (m_Started)
         //Draw a cube where the OverlapBox is (positioned where your GameObject is as well as a size)
         Gizmos.DrawWireCube(Cube.transform.position, Cube.transform.localScale);
     }
 
 }

And this is my CharactersStats class: public class CharacterStats : MonoBehaviour { public Slider myhealthBar;

     public int maxHealth = 100;
     public int currentHealth { get; private set; }
 
     public Stat damage;
     public Stat armor;
 
     void Awake()
     {
         currentHealth = maxHealth;
     }
 
     void Update()
     {
 
         if (Input.GetKeyDown(KeyCode.T))
         {
             TakeDamage(10);
         }
     }
 
     public void TakeDamage(int damage)
     {
         damage -= armor.GetValue();
         damage = Mathf.Clamp(damage, 0, int.MaxValue);
 
         currentHealth -= damage;
         Debug.Log(transform.name + "takes" + damage + "damage.");
         Debug.Log(transform.name + "at health" + currentHealth);
 
         if (currentHealth <= 0)
         {
             Die();
         }
 
     }
 
     public virtual void Die ()
     {
         // Die in some way
         // This method is meant to be overwritten
         Debug.Log(transform.name + "died.");
 
 
     }
 
 }