nǎ​mén​zi

what kind of

哪门子 (哪門子) nǎ​mén​zi
what kind of pronoun
used rhetorically to express disbelief, skepticism, or dismissal regarding the validity, identity, or nature of something

哪门子英雄

suàn nǎ​mén​zi yīng​xióng?

What kind of hero is he supposed to be?

why on earth pronoun
used in rhetorical questions to challenge the reason or necessity for a sudden action, behavior, or emotion

What are you getting so angry about for no reason?

Frequency

Movie subtitles
2.47 per million appears in 1% of films
Written text
0.658 per million

Sources

Definitions
CC-CEDICT