Observation by my elder son, Raynor (8 years)
He told me that Blaziken are "boys". When I ask him how he know, he just pointed to "that place" and said that there is a "Kuku"(penis in Hokkien) there.
Excellent add by the artist. Now at least I don't have to answer the question myself.
More to the "male" Blaziken. (Link)