な Adjectives
The term for "na-adjective" in Japanese is na-keyoushi ナ形容詞, abbreviated na-kei ナ形. They're also confusingly called "adjectival nouns" in English and "adjectival verbs" in Japanese, keiyou-doushi 形容動詞, abbreviated keidou 形動.
In Japanese, the phrase kono ore da! この俺だ! translates literally to "it's this me!" But that sounds weird in English. So, in this post, I'll explain what kono ore means and how it works.
In Japanese, zawa.. zawa.. ざわ・・ざわ・・ is an onomatopoeia for when a crowd gathers and starts whispering around, creating a commotion, however, it's best known for its usage in the gambling series Kaiji, in which case zawa-zawa shows up in tense, cold-sweat-breaking, anxiety-filled situations, even when there is no crowd around, so there's nothing to emit a zawa-zawa sound.
In the anime adaptation of Kaiji, someone voicing the syllables zawa-zawa is used as the sound effect
In the manga and anime JoJo's Bizarre Adventure, Dio says muda muda muda muda 無駄無駄無駄無駄 as his stand goes around punching people in the face. This translates literally to saying "it's futile" repeated many times, but in the series it's used like ora ora ora ora by Jotarō and his Star Platinum, just a thing to say while throwing punches..
Note that although this muda muda muda muda doesn't really mean anything besides the word muda repeated over and over, a single muda 無駄 does mean something in Japanese.
If you've ever watched JoJo's Bizarre Adventure, specially Stardust Crusaders, you've probably already heard Kujō Jotarō 空条 承太郎 and his stand, Star Platinum, screaming ora ora ora オラオラオラ at everyone they punched.
And you might have asked yourself: what does this ora ora ora mean in Japanese?
The answer is: not much.
In Japanese, dodododo ドドドド is normally an onomatopoeia for a thumping sound. This could mean a heart thumbing, or of motorbike cylinder engine, or anything like that.
In the manga JoJo's Bizarre Adventure, dodododo isn't an onomatopeia, it isn't the sound of anything, but is used instead as a mimetic word for when something sudden and unexpected happens, something mysterious, of "real form unknown," shoutai-fumei 正体不明, and so on.
A number of comedy manga parody this usage from JoJo, so, most of the time, dododo means this even when the manga isn't JoJo. (they also often parody gogogogo ゴゴゴゴ, by the way, another sound effect JoJo uses.)