Brief spoilers, can't incriminate my source:
- the immense haki Gaban felt was from someone familiar, he says
- it is revealed to be Oden's haki
- when Gaban says it vanished Zoro gets a concerned look on his face
- last page, in a beautiful double spread, we see Enma in full detail with the haki button turned off
Editor's note: Left to his own devices!