The Brawler title is now permanent.
WHAT TITLE, How do I get this!?
Think you get it from killing the rare bosses.
Google "brawler title"
That seems to be the most up to date information on it. The next two results are a wowhead link to the title with the same things as the official forums and then your thread.
Pokemon FC: 5112-3501-2407 Trainer: Oli FS: Viscoe - Farfetch'd/Hoothoot/Rufflet - Currently Full, DO NOT ADD
Secondary 3DS: 3668-8923-2263 FS: Slider - Phanpy/Camerupt/Diggersby
Avatar not currently but usually by Kyoht.