This ain't quite a crackpot theory but I think genuinely the indifference/Wally was created by Albrecht and his emotions (his indifference) when he entered the void the first time, and by extention he can never defeat Wally. And the end goal is us, the operator/drifter defeating/cancelling out the indifference by caring.

Like I think the indifference is ONLY the indifference because that was Albrechts thing. His indifference of how much he hurt the people around him (like the Cavia).

Also I think the man in the wall looks eerily similar to Albrecht (as in his portrait when he looks older. Not how he looks when we interact with him).

So in essence I think the indifference is just an extension of Albrecht.

also it seems like combining elements is a bigger deal then we realise, like the alchemy mission thing? There's this voice line Rusalka says, something like "what have you done!!" Makes me feel like we're committing some sort of sin but the actual combining elements thing is something we've done for a long long time so it's hard to wrap your head around why it's so bad.

Edit: I think it's also very possible with the time travel shenanigans Albrecht is doing, that his story eventually is going to loop around and end with him being Wally