Blade is only a few years older than Sugar, and were pretty young when their parents married each other. The eldest didn’t seem very excited to have another sibling, but the Neapolitan pony grew on him over the years.
Blade was very supportive when it came to Sugar’s identity. In fact, it was so normal to him that the “coming out” conversation basically went like this:
“Blade, I’m a guy.”
“Cool, me too.”
Blade Wing doesn’t give a single shit, but you better believe he’ll go after whoever misgenders or bullies his brother.