Responses
Yea same here. I was like oh come on, really? Suddenly there's a second son we've never heard about? And in one chapter he beats "the big final boss" of the manga before Souma had a proper rematch with his dad?
It's bad story telling when you don't foreshadow an antagonist this important and just drop him in all of a sudden. I'm disappointed the author decided to go in such a...weird and nonsensical direction.

Are you kidding me... I got this thinking that Jouichirou and Souma will have a grand shokugeki and finally have souma win against him someday...
Then suddenly a bomb was dropped and you're telling me something about "Other Son" And then Jouichirou was defeated one-sidedly...Rather than getting excited, I actually felt it's more of a bummer ╮( ̄_ ̄)╭