How does "xxxのオニ" equate to "xxx is bullying/picking on me"?

Question

I was watching a cartoon that said something like:

にいにいのオニ

Chinese subtitles said

妮妮欺负我

I can only guess that オニ is the same as おに or 鬼 to which jedict says:

noun

1. ogre, demon

2. spirit of a deceased person (see also: 亡魂)

3. ogre-like person (i.e. fierce, relentless, merciless, etc.)

4. it (i.e. in a game of tag)

5. Chinese "ghost" constellation (one of the 28 mansions) (see also: 二十八宿, 朱雀) prefix

6. very, extremely, super- (slang) (see also: 超)

I'm still at a loss at how xxx's "ghost" could equate with - picking on or bulling though.

If I remember correctly the person on the cartoon was answered with:

誰のオニ

where Chinese subtitles said:

谁欺负你？

Who's picking on/bulling you?

How does "xxxのオニ" equate to "xxx is bullying/picking on me"?

Answer 1

A + の + B can mean not only "B of A" but also "B as A" or "B that is A". See: What's the difference between 日本人の学生 and 日本の学生 ?

In English, one can say "You liar!", "You bastard!" and so on, instead of saying "You are a liar." In Japanese, "にいにいのオニ!", "お母さんの嘘つき!", and such work exactly like these — to abuse someone — except that the second person pronouns (あなた, お前, 君, etc) are rarely used in such situations.

This オニ is indeed Oni, and expressions like this usually refer to someone who is unkind and merciless.

誰のオニ doesn't make sense to me. Maybe you have misheard something.

Answer 2

「誰々の ～ 」is a way of saying that someone is "acting like ～ "

Maybe you have heard or seen something like, 「お父さんのバカ！」
which means something like "Dad, you're being such an idiot!"

So,「にいにいのオニ」and 「誰がオニ？」would mean something like, "Nini is being an oni" and "Who is being an oni?"

Where "oni" means something like this:

Answer 3

In this sentence,「の」means "is". It is not the possessive in this case.

So「にいにいのオニ」can be interpreted as "Brother, You're a demon (ogre-like person)!"