Upon being asked "What do you want to do/be in the future, the character answers the right part.
"For now I want to get out of this orphanage and live an enjoyable life"
To which the character then replies
具体性がない which is akin to "You are pretty superficial"
Then the character said
そういうルカはあるのかよ
ルカ then says he wants he wants to join the knights.
However what is going on with そういうルカはあるのかよ from context I can gather he's asking back the question "what do you want to do for the future on other hand?" but I don't see why そういう is being used here
The bubbles are a back and forth between the two characters and the character ルカ said the knights line and the 具体性がない line.