I don't know what "mastered lucid dreaming" is considered. Personally when I started out I found people that had attained the goals I was looking for and asked them. People like Hukif, Oreo, Sivason, sageous, naiya, iadr, writersblock, ravenknight, Max ツ, and many others.

If you are looking for someone that can LD at will, then I am here. I can LD any night that I sleep enough and will to do it. I normally have about 7 LDs a week, but I have had up to 13 in one night. But those that I mentioned above are at a level above me, but not for long, I felt a breakthrough last month and I lost it because of sleep schedule. Simply put, I hate sleep.