Responses
We had it, green witch arc
yes but it's not as detailed as the flashbacks of Meyrin and Bard. We just know he ran away from a scientist lab and that it.
Maybe that's strangely enough oooooor main plot related, like where undertaker took all this advanced technology and stuff. Also Finny was practical a baby in that lab, he doesn't know anything of his past years, we have seen plenty about his life after Ciel and Sebastian took him to the mansion
thank you Yana for reminding us once again that Snake is dead. But why don't we have a flashback for Finny?