MoveSwordWithMouse.cs

using UnityEngine;
using UnityEngine.InputSystem;

public class MoveSwordWithMouse : MonoBehaviour
{
    public GameObject plrRef;
    public Camera cameraRef;
    public float distAwayFromPlayer = 8f;
    //
    public PauseSystem pauseSystemScript;
    //

    private void Update()
    {
        if (pauseSystemScript.GetGamePausedState()) {return;}

        Vector2 mousePos = Mouse.current.position.value;
        float zDistance = Mathf.Abs(cameraRef.transform.position.z - plrRef.transform.position.z);

        Vector3 thingToPass = new Vector3(mousePos.x, mousePos.y, zDistance);
        Vector3 worldPos = cameraRef.ScreenToWorldPoint(thingToPass);

        Vector3 direction = (worldPos - (plrRef.transform.position)).normalized;
        // ---- //
        float angle = Mathf.Atan2(direction.y, direction.x) * Mathf.Rad2Deg;
        // ---- //


        this.gameObject.transform.position = (Vector2)plrRef.transform.position + (Vector2)direction * distAwayFromPlayer;
        this.gameObject.transform.rotation = Quaternion.Euler(0, 0, angle);
    }
}