I think there’s evidence found for the origin of “彁” as the result of a poor scan of a newspaper article. Look up “彁 新聞” to find some japanese sources about this.

Ghost characters reveal something about the joint semantic and phonetic nature of most Chinese characters. I know 彁 isn't real: but it still insists on a pronunciation: ka in Japanese, (gē or gé Mandarin). And it hints at meaning: bowed weapon, sound, elder brother; but your guess is as good as mine!

The article mentions "an example of 彁 mistakenly used in a digitized Taisho newspaper due to a faded printing of 彊", but to me that implies the symbol already existed before then.