ZCopyCat

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class ZRotationCopycat : MonoBehaviour
{
    [SerializeField]
    Transform target;

    void Update()
    {
        var angles = transform.eulerAngles;
        angles.z = target.eulerAngles.z;
        transform.eulerAngles = angles;
    }
}