Yes muscle relaxers can be bad for you liver especially when you take too many muscle relaxers.
That's one of the side effects that are serious side effects from taking muscle relaxers is liver damage that can potentially occur.
So you have to weigh the risks against the benefits of taking the muscle relaxers.
If you already have liver disease or other liver health issues then your doctor may not want you to take muscle relaxers as they could cause further liver damage.
When your liver gets damaged it can lead to death if you don't get a liver transplant.
It's rare though that you will get liver damage from taking muscle relaxers but it is a potential thing that can happen.