Champ.cs

class MainScript : MonoBehaviour {
  public static MainScript instance;
  
  void Awake() {
    instance = this;
  }
  
  public void OnSelectChamp(Champ champ) {
    // ignore if state is not a `picking`
    if (state != "PICKING_CHAMPS") return;
    
    // write your code here
  }
}

class Champ : MonoBehaviour {

  public void UseAbility() {
    SendMessage("_UseAbility");
  }
  
  void OnMouseDown() {
     MainScript.instance.OnSelectChamp(this);
  }
}

class BoostAbility : MonoBehaviour { 
  
  public void _UseAbility() {
     /* Ability codes here */
  }
}
class DeboostAbility : MonoBehaviour { 
  public int amount = 5;
  
  public void _UseAbility() {
     /* Ability codes here */
    
    Referee.instance.opponent.Deboost(amount);
  }
}


class Referee : Mono {
    public static Referee instance;
  
    
}