A mentor should be someone who has successfully accomplished a goal that you wish to accomplish or have great insight. I personally would like a mentor that is helpful, patient, provides good direction, and doesn't mind communicating with me.
Could take some of what Patrick Bet-David mentions in his videos.
How to Find and Keep a Mentor - https://www.youtube.com/watch?v=e0jZ1lNqsE4
How to Choose a Mentor- Seek Trifectas- https://www.youtube.com/watch?v=I0qXYL_TuxM
How to Find a Mentor- Q & A - https://www.youtube.com/watch?v=SX3LjUdT6Qw
I believe that the most important traits of a great mentor are:
1. Willingness to learn: knowing that one does not know everything, and is capable of being wrong, even as a mentor.
2. Shared vision: in pursuit of the similar goals in life and work.
Unfortunately, these are not discernible without personal experience with a given mentor, since preaching such traits is not the same as practicing them.
To me, a mentor is someone that is living the life that that you want to live and is quite a bit older. They've already accomplished the goal you set out to reach. It could be that they've created a lifestyle that you want. They are the people you ask advice on for the large life decision moments.
For example, do you like the relationship they have with their spouse and kids? Have they created a business that allows them to spend time with their family? Think about exactly what you want to accomplish in your life before seeking out mentors.
If you're looking for someone to give you marketing or sales or HR advice, you're more seeking an advisor that knows a particular field.
Let me know if you'd like to talk about how to find top notch mentors.