I'm wondering about a specific ruling of Dazzling Display, due to the wording of the feat.
Feats where you need to select a specific weapon or skill to work with it generally say so in the feat itself, such as Weapon Focus having the following text:
"Choose one type of weapon. You can also choose unarmed strike or grapple (or ray, if you are a spellcaster) as your weapon for the purposes of this feat."
Weapon Focus can also be chosen more than once, if you want to focus on multiple weapons.
Dazzling Display on the other hand doesn't, but it does have the same "proficiency with the selected weapon" prerequisite that Weapon Focus does. Apart from that, it merely states "While wielding the weapon in which you have Weapon Focus(...)"
So, if someone happens to have more than one Weapon Focus, do you still ony take Dazzling Display once, and able to use the feat with any weapon that you have weapon focus in?
If yes, would that also mean that a Cockatrice Cavalier (who gets DD as a bonus feat from their Braggart ability) who has Weapon Focus could also choose to use it with a weapon if they so choose (as a full-round action, rather than the Braggart standard action)?
I think it's ambiguous RAW but would say it is entirely reasonable to think that if you have Dazzling Display any weapon you have weapon focus in would count. I'd see it as having the panache to turn your skill into something that others take notice of rather than just being 'stolidly effective'. I can't see any advantage in wanting to use a full round requiring weapon over a standard - although as I write I can already think of two (in a silence spell, or underwater) - so scratch that.
I think that a CC using DD with a weapon is probably against "rules as intended" but I suspect the wording does not rule this out and it's not *that* great so as a GM I would probably accept it.
"While wielding the weapon in which you have Weapon Focus" is pretty generic. I would think that if you have proficiency and Weapon Focus with multiple weapons, that Dazzling Display would work no matter what.
For a Cocatrice Cavalier, it doesn't even matter. They don't need to wield a weapon to use Dazzling Display via the Braggart ability in the first place. Why would you want to waste a full-round action on something that is only a standard action for them?
I think the point of dazzling display, is BECAUSE you are focused with that weapon you can swing your weapon around all intimidating-like and intimidate foes.
If you have focus in more then one weapon, they would all for for Dazzling Display as you are focused in more then one, (so of the same skill level in wielding) and therefore could swing around any weapon you are proficient in the intimidate opponents.
To answer your question yes you only have to take Dazzling Display once, and it works with any weapon you have weapon focus in.
I agree - Dazzling Display only needs to be taken once, and can be used with all the weapons you have the Weapon Focus feat for. I would go even further and say that if you took Weapon Focus in a new weapon after you already have the Dazzling Display feat, you can use it with the new weapon too.
I think that a CC using DD with a weapon is probably against "rules as intended" but I suspect the wording does not rule this out and it's not *that* great so as a GM I would probably accept it.
The only reason I figured it'd be usable normally rather than being a fully separate ability is in the wording of the Braggart ability, which states "You gain Dazzling Display as a bonus feat". If it was completely separate, they could just have given the ability the same mechanics (since DD already has the same mechanics as demoralizing via Intimidate).
Anyway, thanks everyone for the replies. Feels like my reading of it is the same as most of you. I think honestly the ambiguous wording could easily enough be fixed by changing "wielding the weapon in which you have Weapon Focus" to "wielding a weapon in which you have Weapon Focus".