How do you translate this?

[Gettersaga]

I was reading a japanese novel and everything was going well when I've met a phrase I really don't know how to translate. It's a small (well not so small) phrase but it has stopped me.
Can you help me. More I look at that, more it seems to me that it can't be translated.
まさか、その何某先生が鬼ような醜悪の才能を持ってい るという事実を暴露し、以て世人に警告を発するつもり で、その案内欄の鬼才などという怪しむべき奇妙な言葉 を使用したのでもあるまい。
The まさか in the beginning and the のでもあるまい in the final part are the points that don't make me understand the meaning of the phrase.
(demoarumai should be something like demonaidarou, if I remember well but it doesn't help me so much).

[Nagoyankee]

Originally Posted by Gettersaga

まさか、その何某先生が鬼ような醜悪の才能を持ってい るという事実を暴露し、以て世人に警告を発するつもり で、その案内欄の鬼才などという怪しむべき奇妙な言葉 を使用したのでもあるまい。

This is quoted from Dazai, isn't it?

If you really understood the sentence immediately preceding this one, you shouldn't have too much trouble. Hope you sensed the light humor in it.

The preceding sentence, in summary, says that people think that all ogres （鬼） are creatures of ugly and detestable nature, but at the same time, people use the term 鬼才 to describe the authors of the highest rank.

Now the sentence in question means:

"Surely they couldn't have used the suspiciously odd term '鬼才=genius' in the New Books section of the newspaper in order to reveal that a certain Mr. Author possesses the ugly capacity like that of an ogre, and hence warn the public of the fact."

[Gettersaga]

It's how you are saying
"This is quoted from Dazai, isn't it?"
It was quoted from Otogizoushi, in fact.

If you really understood the sentence immediately preceding this one, you shouldn't have too much trouble. Hope you sensed the light humor in it.

I had perfectly understood the meaning of the previous sentence.

The preceding sentence, in summary, says that people think that all ogres （鬼） are creatures of ugly and detestable nature, but at the same time, people use the term 鬼才 to describe the authors of the highest rank.

I had understood it exactly in that way.
I disn't understand how to connect and translate masaka to demoarumai. Dazai, sometimes, uses sentences extraordinarily long. And it is a sentence, well a series of sentences connected each other, really long.
So I started to think to tne most unbelievable ways (and they were all unbelievable, every time I thought how to translate it I complicated more and more all) to read that sentence in the whole context.
Thanks a lot, Nagoyankee.