@Fujishiro @TheKnightOfTheSea
We still need to see the Gorosei's backstory, how they became Imu's top subordinates, as well as why they are immortal, and how to get past their immortality regen.
However this arc isn't going to do that, the Gorosei will get their focus again in the future and the second time they get their major focus is when we will learn more information about them while at the same time they finally get defeated.
To me, this is arc with the Gorosei is just Oda teasing them for the future.