Kaidou said the same thing to the Red Scabbards. Lol
That is exactly where the irony is, he is not. LOL
And Luffy is going to prove it. Blow after blow, Imu will fail to defeat Luffy. Imu simply dug his own grave. A fish dies by its mouth. The mouth of a fool is his ruin; he falls into the trap of his own lips.
With one leg or two missing, with 50 power-ups or none at all, in the end, Imu will be kicked out of this country, that is, if he is not defeated right here. And at the end of the day, an EMPEROR will be the one to do it. The Yonkou win triumphantly in the end.