@Background Pony #ACB4  
Older brother, perhaps?

@Background Pony #D77F  
well, according to an interview with the staff, he’s not her father… so he’s a mentor, but NOT her dad.  
http://www.equestriadaily.com/2016/09/character-designer-kora-kosicka-rainbow.html

Look like the card are really canon with the show after all.

@Background Pony Number 17  
Well, he was in season 6, but only in background for a second in “A Hearth’s Warming Tail”.

Ncydjfxknhv any drug vhffknugzdj

@Background Pony Number 17  
I don’t think “spoil” would be the most accurate thing to say. I’d say it’s likely that they don’t have any more idea than we do about how Blaze is related to Dash. Thus, they keep it ambiguous in order to preemptively avoid any conflict with the show. After all, the folks making the card game don’t necessarily have full access to the folks writing future episodes.
 
For example, imagine if the folks making the card game state that Blaze is RD’s dad, but then the show writers put Blaze into an episode as RD’s older brother. Whoops! If that happened, there’d be a bunch of confusion, someone official would have to clarify things, and we’d end up with a bunch of fan fics and theories about how Rainbow Blaze is named after his dad and looks exactly like him, or that Blaze is RD’s Dad AND Brother at the same time, etc.
 
By keeping it ambiguous, they lessen the chance of stepping on the showwriters’ toes.

Daddy man!

Okay, so is he Rainbow Dash’s dad, older brother, or some other male relative? “Dashing Mentor” is ambiguous.
 
Or is this deliberate, and they’re trying not to spoil something that’ll hopefully be revealed in Season 5?

@Background Pony #C0EF  
Nothing is wrong with gold eyes I just think something different woulf go with his color scheme better

@Background Pony #8FAA  
Maybe it’s family name first and given name second, like in Japan. Or something.

@Applejack007  
What’s wrong with gold eyes?
 
Wait, gold eyes? Derpy and Dash are sisters!
 
…What? We’ve made bigger fanon out of less before.

I wish his eyes were a different color. :\

@Background Pony #B183
 
Was that an X-Men quote I saw?
 
-Lumino

Yes. But the real question is: did you teach her everything YOU know?

@Background Pony #73AD  
Hardly. Hers is a cloud and a lightning bolt, his is a cloud and a streak.

Wait, is his cutie mark the exact same one as dash’s :/

@Millennial Dan  
And let’s not forget every last one of the Cakes…

@Background Pony #8FAA  
Twilight Sparkle  
Twilight Velvet
 
Apple Bloom  
Apple Jack
 
Pinkie Pie  
Maud Pie
 
Happens a lot, among family members.

@Background Pony #8FAA  
Yeah and Twilight Sparkle being named off of Twilight Velvet isn’t?

@Background Pony #8FAA  
No less egotistical than Twilight Velvet naming her daughter Twilight Sparkle.

@Background Pony #8FAA  
Maybe its a family tradition?

Is it just me or him naming his own daughter after himself, is a bit egotistical?

Yeah, not a bad name. I can dig it.

Bout time.