Maintenance for the week of September 1:
• [COMPLETE] Xbox: NA and EU megaservers for patch maintenance – September 3, 4:00AM EDT (8:00 UTC) - 12:00PM EDT (16:00 UTC)
• [COMPLETE] PlayStation®: NA and EU megaservers for patch maintenance – September 3, 4:00AM EDT (8:00 UTC) - 12:00PM EDT (16:00 UTC)
Brawler creates a shield depending on how many enemies you hit with it, but does the shield keep increasing as you recast Brawler or does it just refresh the shield with a new cast?
Any consecutive cast of Brawler does not add a new shield until the previous shield has dissipated.
So my advice is to time and aim it well to get the most shield-points every time you use it.