Shirahoshi is Poseidon??
The revelation that a giant hapless barbie doll is one of the three ancient weapons was so disappointing.
If she ever comes back into the series, she better be as dangerous as Luffy.
Say ten Hail Marys, five Our Fathers, and the Gilligan's Island theme
Uh... did you perhaps miss this bit?
https://shannaro.files.wordpress.com/2011/11/shirahoshi-power.jpg
She doesn't need to be "as dangerous" as Luffy, because that's not how she is, and how her kin likes to act. As a matter of fact, that would mess up their chances at the Reverie.
With that being said, Shirahoshi can summon/control all the Sea Kings. Do you know how monstruous and hostile these creatures are, and what it would mean to have a whole army of them under your command? Like, one of these creatures alone bit off Shank's arm, so what does that say about having to face hundreds, if not thousands of them?
That's dangerous enough as it is.
Fine, fine, I'll leave! But first I'm going to bother these peanuts! Hmm? Yes? Hmm? HMM?