@andy:
With croc you can say he did .
He was not knock out but he was as good as dead if not for robin the first time.
I wouldn't call it a one shot by any means
Crocodile used a couple of different techniques to try and kill Luffy before impaling him, and even that was achieved when Luffy completely let his guard down over his worries about the sandstorm
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@Razh:
Reduce it somewhat, I could see.
I'd be ok with reducing it to the point where Luffy could beat him as part of a team effort and deal the final blow
@Razh:
The gap between Katakuri and Luffy seemed too big to surpass too. In the end I didn't like how it was handled, hope that doesn't repeat.
This is true, but this gap seems even bigger
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@andy:
I won't say it's his trump card transformation.
At this point boundman has become his go to mode.
He may have other stuff he can do but he did not get the chance .
EDIT now that i look at it he has not beaten anyone with just boundman .
It's his top transformation in terms of mixing strength and speed
I'd call it his trump card, personally