A legal advisor is someone who advises people on the various intricacies of the law. One of the most common forms of legal advisor would be a court legal advisor. In this case, the advisor explains the law to magistrates and district judges who often serve on a voluntary basis and so might not be completely up-to-date with all the current shenanigans in the legal world.
All legal advisors must be fully qualified and would be required to offer advice on possible sentencing to a judge but they would never actually rule on a case themselves.
As this is a legal role, their first responsibility is to fully understand the law they're delineating on. A legal advisor must fully understand the situation they are offering counsel on, as mistakes could seriously impact someone's life.
They would also assist in drafting a Justice's reasons for making their decision and would deal in legal aid applications. Research is another key area of this role and a legal advisor must be constantly seeking out changes on legal issues and current case law. They must be able to assimilate this information quickly and explain it to people who are not necessarily all that familiar with complex laws.