User blog comment:Kaido King of the Beasts/Chapter 908: Imminent, Imbalanced, Improbable Whims/@comment-3185063-20180615081043/@comment-29325824-20180615140514

I know I'm mostly grasping at straws, but it's the best I can think of to give a reason for Blackbeard still being able to be a threat to someone like Im.