Super Duper Important mean Imu importance. I believe Akainu and Blackbeard will have an equal type of importance, and i believe a lot of thing about Akainu. I dont low ball blackbeard.
Blackbeard, Akainu and Imu are the 3 main antagonists of OP. Its not a coincidence they are the 3 final bosses of OP.
But I have an argument of why BB is the final one.
Now we know that happened 2 flood/2 war in the past, right? And that existed 2 nikas. Imu was already confirmed as one of the 20 kings that created the wg. So Imu is from Joyboy era (the second Nika). That means the first Nika had another enemy. Who is this person? Its not Imu.
So what I'm trying to say is that in every flood era there was a Nika and Nika's nemesis. So Luffy will get his own nemesis, and can't be Imu.
First Nika -> Unknown enemy
Second Nika (Joyboy) -> Imu
Third Nika (Luffy) -> Teach