Remember his glowing mane from the first artwork? =3  
That actually has a purpose to his character make-up, something that has to do in relation with how his special talent represents (which I still have to show you guys that ^^; )
 
As a pegasus pony, he works in the weather patrol specifically for the time when bringing in sunlight to the land. In his muscular form gained from a concentrated unicorn blast, he is somehow able to transmit that energy, combining his special talent to instead . . creating light!  
This is one of what he can do so far. x3
 
Also, in case if you’re wondering if his name “Flex” has something to do with all of this, well, actually it doesn’t. He called himself that when he got accidentally buff. He has a real name. The title indicates that. ^^
 
. . And other than all of those above, enjoy this new rendering style~! ^u