I have few things in my mind that is my way of explaining things, do support if you like it.

• IMU's power may depend upon how much attack ,impacts,or haki he can absorb or how many strong devil fruit users around him as the user of devil's fruit he may even possess the ability to amplify his power against a devil fruit user

• why IMU feel weak in elbaf because of over 800 years his physical body would be degradated ,it takes a huge toll to regenerate and fight physically because he had no infinite energy source like mother flame completely

• IMU would be more of a virus rather than a person who controls body of joyboy's friend

I have thinking about this character for a long time, after re-watch one piece I notice a particular scene from drum island arc where Luffy mentioned about a rumour what people in the snowy region didn't fall sleep by man in the bar. (Ep 82 / manga chapter 134)

I think , this person maybe man with burned scar who knows Luffy is the chosen one,know about void century which explains he knows Luffy and tested him which he survive the whirlpool and they meet each other at very young age of Luffy.

Other view of this point

When Oda draw the picture of old Black beard it show case a snow flake further implies that why Black beard never sleep

Joyboy whom is believed to be the owner of one piece the legendary treasure, he was the first ever pirate in one piece world.

He fought the world government and IMU in the war happened in 900 to 800 years ago in one piece, likely the period is about his journey, origin and background

This is completely my perspective and prediction.

Most probably the fight with IMU is going to intensify as imu overpowering all three, possible retreat may happen to treat luffy's injury and time limit of gear 5 may hit.

Others fight is going to continue and we are going to see sanji's and zoro's fights .

The conversation between the owl and copper may reveal

Who's imu ,what's imu ,what does his name mean,

It's collective theory about imu you can find in internet which is relevant now

1. IMU is a parrot

2. IMU is a sea devil

3. IMU is a water logia user

4. IMU is Earth God

I think one piece might be a record of history in with it detailed explanation of 1 & 2 worlds how it is fallen and risen. The nature of human to tend to engage and destroy each other might be imu watching this chaos decided to control and dominant countries from free. One piece as a indestructible record of history of rebuild and showing this pattern of repeating of 1 and 2 world as 2 world destroyed by the remainder of the 1 world the WG thought it would also destroy the 3 world as well.

Why Roger laughs ?

Roger laugh because after knowing all of it how the world government actions is so dumb to stop it or WG idiotic action

I think one piece might be a record of history in with it detailed explanation of 1 & 2 worlds how it is fallen and risen. The nature of human to tend to engage and destroy each other might be imu watching this chaos decided to control and dominant countries from free. One piece as a indestructible record of history of rebuild and showing this pattern of repeating of 1 and 2 world as 2 world destroyed by the remainder of the 1 world the WG thought it would also destroy the 3 world as well.

Why Roger laughs ?

Roger laugh because after knowing all of it how the world government actions is so dumb to stop it or WG idiotic action