its because when going to the abiss he knows both the plain and the place on that plain that he is going to. when going to the plains of man he needs some kind of link to follow to the right plain and place on that plain. its easier with the abiss because its there is only one abiss were as the plains of man is divided into a multitude of universes that you need to sort between to get anywhere.
So when running from the rod he imagined burning a hole thro the vail into the abyss my question is why he cant do that in reverse without needing a link? Seeing as he technically doesn’t have a link to his home in the abyss its just imagining his destination hard enough.