Hi guys, second topic of my series i forgot bout.
The bromon master badge is a badge only obtainable by completing the bromon extension (by catching them all), and showing a screen shot of it on the Request Your Bro-Mon Master Badge Here! 
topic, the badge was obaiable for a long time and still is, it is a way to tell everyone you have became a master of bromon and probaly means you are dedicated to bromon!