Well didnt the brother say that one of the scientists gave their son to his brother in law to replace his son who died
I would have said that Paca was a different person, based on Niki's explanation, but now that I reread it again, it seems he just used "that person" and didn't exactly mentioned who exactyl it was, but based on the conversation, he might be refereing to akatsuki's foster father,
So maybe you're right...
and that scene when he said "that person probably hates me now" kinda looks like when Paca released him(?) from the island... or maybe that person he's referring to is his friend who he left behind at the underground tunnels...
Yes! You got my point! But I am not really sure about this speculation, afterall it's just a speculation ╮(￣▽￣)╭
We all know that Akatsuki's foster father is dead because of laboratory incident, right?
And Yuzu's sister is with somebody on the picture (which looks like Akatsuki)
Look at Chapter 30 again, Paca had a dream, a glimpse of a burning person in a laboratory and you can see a Akatsuki look a like saying something to a girl which looks like Yuzu' sister.
Maybe Paca is th foster father of Akatsuki? And you know what the brother of Akatsuki's mother said, "Dead People Walk All Around it", which probably meant the masked or hybrid game operators because they had shown a lot of them (When Karin's big bro played the game)