What is language "DUWANG"

[T.OHNO]

Hi
Now I'm playing goofball mode but I can't catch the meaning of language mode "DUWANG" in preference.
If this mode was turn on, I noticed that some abbreviated expressions changed to formal ...but is that all?
if you have any ideas, pleeeese teach me, thx.

[Halimede]

It's a JoJo reference. It's based on a ♥♥♥♥♥♥ English translation of the Part 4 translation, where one of the characters is meant to say "What a beautiful day" but it's translater as "What a beautiful duwang". Part 4 manga is known for poor translation, so it's a on-purpose poor Japanese-to-English translation, meant to be played for laughs.