EnemyUnitExample

public class EnemyUnit
{
  public bool Enabled; // Is the object active within the environment?
  public bool IsAlive; // Has the object been killed yet?
  public bool CanBeHit; // Can the enemy be hit or is it currently invulnerable or dead?
  
  public void OnHit()
  {
    if(Enabled)
    {
      if(IsAlive)
      {
        if(CanBeHit)
        {
          DoDamage();
        }
      }else
      {
        if(CanBeHit)
        {
          PlayCorpsehit();
        }
      }
    }
  }  
}

EnemyUnitFSM

public class  EnemyUnitFSM
{

  public enum States
  {
    Alive,
    Hit,
    Dead,
    CorpseHit
  }


  public void OnHit()
  {
    if(stateMachine.CurrentState == States.Alive)
    {
      stateMachine.SetState(States.Hit);
    }else if(stateMachine.CurrentState == States.Dead){
      stateMachine.SetState(States.CorpseHit);
    }
  }
  
  public Task Hit_Update(CancellationToken ct)
  {
    doDamage();
    if(stateMachine.CurrentState == States.Dead)
    {
     return;
    }
    await playHitAnimation();
    stateMachine.SetState(States.Alive);
  }

}