Legally speaking, if the pictures of online characters have been published and passed the validity period, there should be no infringement involved.

However, it is not allowed to use the original (the person without official application) as the main picture for personal use.

If you do design, it depends on whether you are profitable or not. If you are profitable, it definitely constitutes infringement. I advise you not to do this.

Moreover, many of these cases are televised, and the specific judgment depends on whether the parties hold the users accountable. If they don't pursue it, nothing will happen and they can use it with confidence.