How is “斜め上から” and “ていうの?” used in this sentence ?

"なのに 作戦を立てさせると よくもまあ思いつくわって感じの 斜め上からっていうの?"

I am a bit stumped by the" からっていうの?" I know 斜め上 means surprisingly or out thing air but 斜め上から does not show any result whe i try to look it up for this meaing only to mean from above or from an angle above so how is this sentence parsed ?

by Interesting-Cat7307