That's actually very interesting.

(That whole situation ~ Pic).

If you think about it, We don't really know why THEY are the ones chosen by Ember and Thorax.



I guess we will be told later in S8.





Of course, if Hasbro will decide to let us know.

And something tells me they actually will eventually tell us.

Why ?

Well, Season 9 is - for now - suppose to be Final Season (then Gen-5)



So, I very much doubt they would leave that kind of information for Final/Most Important Season.

{Also, we did get some info from Hasbro, and according to their Twitter, before Mid-Season 9, they'd like to Answer all of the still "On-going" Questions. }



All of the others were from the Important/Royal Blood, but they just ARE.