Who would あやつ reffer to in this context and other considerations

Question

I have the following scene. Three ancient persons were roused (by persons K and I) from a place they were resting in for a LOOONG time. Specifically the logical/knowledgeable one mentions that it seems that "2-3 cycles of reincarnation" have passed (２～３回は輪廻が巡る月日). I should note that the franchise in question is not religious at all so I'm just assuming this is a fancy way to say that entire eternities might have passed.

The same person also notes that it's likely that given the time that has passed that they themselves have changed/were tampered with during all that time.

To this all the leader comments:

まったく… ”あやつ”に関わると摩訶不思議な事ばかり…

at the last ellipsis she cuts off because she is suddenly struck with an kinda unrelated vision/memory.

From what I was able to determine あやつ is the kinda old timey third person way to speak abusively or disparagingly about someone. The old timey aspect fits because this character does have a tendency to mix in arhaic expressions.

What I'm wondering is who does the word reffer to. And how to translate this.

I have a feeling that she might be trying to say:

Good grief, whenever you tangle with the rabble/those bozos, mysterious things (are bound to happen).

with the bit in the parenthesis being what I think she might have said if she wasn't cut off.

I also think that she isn't directly reffering to K and I, given that they just roused them, and have only now met them so they kinda don't fit.

Answer 1

Yes, あやつ is an old-sounding version of あいつ. More precisely, あいつ in modern Japanese is an euphonic sound change of あやつ.

I don't know who this あやつ refers to, but since it's enclosed in double-quotes, I feel the author is aware that this あやつ may seem confusing. So it's possible that it's referring to someone who has not appeared in the story yet, for example someone she met several "cycles" ago, someone who has something to do with that "kinda unrelated vision/memory". If this is the case, the subject of 関わる is I or we, the roused one(s).