Anyway to make oncollision damage is done which will remove health?

I am looking for a way where on2dcollision health is removed, similar to that of diep.io any references or personal solutions would be very appreciated. Thanks.

GM Script:

 using UnityEngine;
 using System.Collections;
 using UnityStandardAssets.ImageEffects;
 
 public class GameMaster : MonoBehaviour {
 
     public static GameMaster gm;
 
     void Awake () {
         if (gm == null) {
             gm = GameObject.FindGameObjectWithTag ("GM").GetComponent<GameMaster>();
         }
     }
 
     public Transform playerPrefab;
     public Transform spawnPoint;
     public float spawnDelay = 2;
     public Transform spawnPrefab;
 
     public IEnumerator RespawnPlayer () {
         GetComponent<AudioSource>().Play ();
         yield return new WaitForSeconds (spawnDelay);
 
         Instantiate (playerPrefab, spawnPoint.position, spawnPoint.rotation);
         GameObject clone = Instantiate (spawnPrefab, spawnPoint.position, spawnPoint.rotation) as GameObject;
         Destroy (clone, 3f);
     }
 
     public static void KillPlayer (Player player) {
         Destroy (player.gameObject);
         gm.StartCoroutine (gm.RespawnPlayer());
     }
     
     public static void KillEnemy (Enemy enemy) {
         Destroy (enemy.gameObject);
     }
 
 }
 

Player/Enemy Script:

 using UnityEngine;
 using System.Collections;
 
 public class Player : MonoBehaviour {
 
     [System.Serializable]
     public class PlayerStats {
         public int Health = 100;
     }
 
     public PlayerStats playerStats = new PlayerStats();
 
     public int fallBoundary = -20;
 
     void Update () {
         if (transform.position.y <= fallBoundary)
             DamagePlayer (9999999);
     }
 
     public void DamagePlayer (int damage) {
         playerStats.Health -= damage;
         if (playerStats.Health <= 0) {
             GameMaster.KillPlayer(this);
         }
     }
 
 }