Why is 及び being used to mean "a.k.a." in this sentence?


So this sentence in a [Vtuber
video](https://www.youtube.com/watch?v=wRbAa8lYBzI) (which has English and
Chinese translation available) caught my interest:

> 今回の事件ははあちゃま及び赤井はあとがデビュー当初から秘められし能力を封印していたこと原因であり、すべてははあちゃまの責任です。

I initially went into this video to analyze the relationship between Haachama
(はあちゃま; 心酱) & Akai Haato (赤井はあと; 赤井心), two vaguely-defined aliases/personas of
said Vtuber.

If I understand 及び correctly, it is somewhat like a formal version of と in
that it is used to lists several items. So then why does both translations
interpret this sentence as "Haachama _a.k.a._ (also known as) Akai Haato"?
Shouldn't it be "Haachama _and_ Akai Haato"? Surely two items in a list can't
be the same thing (a.k.a.)?

> As this incident was caused by Haachama, Akai Haato keeping **her**
> abilities sealed from debut onward...

> 本次事件的原因 是心酱 **也就是** 赤井心出道时所隐瞒的能力之前一直处于封印状态．．．

If "Haachama a.k.a. Akai Haato" was the original message they were going for,
shouldn't the conjunction between Haachama and Akai Haato be something like
はあちゃまこと赤井はあと, not 及び? Could this possibly be a mistranslation or translation
liberty?




Yes, the original message in Japanese is "はあちゃま **and** 赤井はあと". Someone who
knows nothing about them would think she's presenting the names of two
different people. Grammatically, the English translation is an error.
Practically, it may not be an error if these two names refer to the same
character. It may even be a good translation if saying "and" would
unnecessarily puzzle some of the audience who are not familiar with this "two
vaguely-defined personas".

By the way, when you use こと, please check the word order. "A aka B" in English
means B is the secondary or less-known name, whereas "AことB" in Japanese means
B is the formal name.




Yes, the original message in Japanese is "はあちゃま **and** 赤井はあと". Someone who
knows nothing about them would think she's presenting the names of two
different people. Grammatically, the English translation is an error.
Practically, it may not be an error if these two names refer to the same
character. It may even be a good translation if saying "and" would
unnecessarily puzzle some of the audience who are not familiar with this "two
vaguely-defined personas".

By the way, when you use こと, please check the word order. "A aka B" in English
means B is the secondary or less-known name, whereas "AことB" in Japanese means
B is the formal name.

