Btw is Zoro saying that Oden didn't really mastered Enma he was just so strong to withstand the haki draining ? Or i understood that part wrong ?
My interpretation was that Zoro was trying to figure out how the fuck Oden did it, so i think he came to the conclusion that there's no way Oden was controlling the haki thing all the time like he was doing, basically fighting off Enma.
Oden really became "friends" with Enma, by giving what it wanted and using it for what it was designed to do, that's why the name of the last chapter was "Oden's beloved sword".
So Zoro started doing the same thing, for all 3 blades.