As barbaric as this sounds

Hello teachers,

I don't know how to understand the part unlined.

Is the sentence, especially the part underlined below correct?

Is it the same structure as in 'Poor as he was, he had won the general respect' ?

I need to understand and explain the part grammatically as well as in meaning.

If you could expain it with some grammatical terms, it would be a big help to me.

Thank you!

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As barbaric as this sounds, it should be remembered that many other ancient civilizations practiced human sacrifice.