void Update()
    {
        for (int i = ownedItems.Count - 1; i >= 0; i--)
        {
            ItemBase item = ownedItems[i];

            if (item.State == ItemBase.ItemState.Using)
            {
                item.OnUsing();
            }
            else if (item.State == ItemBase.ItemState.Consumed && item.CheckIfFinished())
            {
                item.ClearEffects();
                ownedItems.Remove(item);
                Destroy(item);
            }
            else
            {
                item.UpdateEffects();
            }
        }
    }