Ever since Benn Beckman’s encounter with Kizaru at Marineford, I was puzzled why would Kizaru fear him that much. Because Kizaru can move at the speed of light, so why would he stop when Beckman tells him to?
Possible ideas were that he has Speed Speed Devil Fruit or something that allows him to see people move at slow motion, like Mihawk’s eyes. Still I was not sure, until this guy appeared:
I think Benn Beckman can, similar to Katakuri, see a bit into the future, and that’s why Kizaru stopped when he was going to attack Luffy, because Benn would, since his intentions, probably fire a Sea Stone bullet from the gun he was pointing at him as well.
Since Shanks himself is the master of Haki, it is not surprising that his crew mates (especially Benn, as he is the first mate) also have a very high Haki skills. Usopp’s father could as well has a powerful Observation Haki that helps him in sniping enemies.
One last thing is how Benn could get so high on the top of the ship in a short time before Kizaru notices him.
I think he could predict that a few moments earlier and thus get up there in advance, he could also have some cool mobility skills to allow him to move quickly. He even made himself comfortable, and by the time he met Kizaru he was already sitting, that means he has been there for a while before the meeting.
*Theory by Zoro.Senpai