So Killer was the one who described Apoos powers to Luffy and Kid and Zoro. He seemed to have a solid knowledge of how Apoos powers worked and how to counter them.
As to why I can see one prime reason:
1. When Kid made the deal with Apoo and Hawkins, Killer chose those two because he already knew how their powers worked. Because of this if they betrayed Kidd he’d be able to help kid fight them 2 v 2.
If this is the case could killer also have an idea on how to counter Hawkins DF power? For example does his devil fruit only transfer physical damage and those sonic blades we saw earlier won’t harm his puppets. Or something along those lines.
It would actually connect back to why Oda would include the fact that it’s killer that knew the power sets of the others and not kidd.
As to why I can see one prime reason:
1. When Kid made the deal with Apoo and Hawkins, Killer chose those two because he already knew how their powers worked. Because of this if they betrayed Kidd he’d be able to help kid fight them 2 v 2.
If this is the case could killer also have an idea on how to counter Hawkins DF power? For example does his devil fruit only transfer physical damage and those sonic blades we saw earlier won’t harm his puppets. Or something along those lines.
It would actually connect back to why Oda would include the fact that it’s killer that knew the power sets of the others and not kidd.

