Whenever you select a feat, you need to fulfill the prerequisites. Whenever you gain a feat, you can ignore them.
There are exceptions for both, but those have to be spelled out.
What a wild talent that is. It's essentially two feats for the price of one, since you're getting both the Power Attack damage bonus and a bonus to AC (albeit "only" a shield bonus, instead of a dodge one) equal to what Combat Expertise would give, for the same penalty.
Unless there's a FAQ out there that covers feats awarded in this manner, I'd say getting that talent, as powerful as it is, is contingent on meeting the requirements for the Power Attack feat. Note how other talents that allow you to gain a feat with prerequisites, such as Shield of Fury, Signature Weapon, Strike the Unseen, Sweeping Strike, Unkillable, and Vital Punishment qualify that you gain their benefits without needing to meet prerequisites. Five of those six talents are in Ultimate Intrigue along with Shield of Blades, so I doubt they simply forgot to include the same design considerations for that one talent.
EDIT:
Point of fact, looking over that list, Shield of Blades is the only Vigilante talent that allows you to gain a bonus feat that has prerequisites that doesn't qualify you can ignore said prerequisites. The only other talents that allow you to gain a bonus feat without qualifying you can ignore prerequisites are ones whose feats have none (e.g., Antagonize, Weapon Finesse). I don't think that's by coincidence.
Unless there's a FAQ out there that covers feats awarded in this manner, I'd say getting that talent, as powerful as it is, is contingent on meeting the requirements for the Power Attack feat. [...]
Point of fact, looking over that list, Shield of Blades is the only Vigilante talent that allows you to gain a bonus feat that has prerequisites that doesn't qualify you can ignore said prerequisites. The only other talents that allow you to gain a bonus feat without qualifying you can ignore prerequisites are ones whose feats have none (e.g., Antagonize, Weapon Finesse). I don't think that's by coincidence.
No. It may be the only such Vigilante Talent, but it's not the only such class feature.
Take a look at the Spellbreaker Rage Power, which says "When raging, the barbarian gains Spellbreaker as a bonus feat. A barbarian must have the disruptive rage power and be at least 12th level to select this rage power." The feat Spellbreaker requires "10th-level fighter". If you need to fulfill the prerequs of a non-selectable feat that you gain form a class feature, that means you need a 22nd level character to make use of the Rage Power. The game only goes up to 20th level. Therefore, this cannot possibly be correct.
What a wild talent that is. It's essentially two feats for the price of one, since you're getting both the Power Attack damage bonus and a bonus to AC (albeit "only" a shield bonus, instead of a dodge one) equal to what Combat Expertise would give, for the same penalty.
Selectable class features are supposed top be stronger than feats. Hell, look at Signature Weapon, outright gives you two feats. So very clearly such an effect is not out of line for a Vigilante Talent!
Point of fact, looking over that list, Shield of Blades is the only Vigilante talent that allows you to gain a bonus feat that has prerequisites that doesn't qualify you can ignore said prerequisites. The only other talents that allow you to gain a bonus feat without qualifying you can ignore prerequisites are ones whose feats have none (e.g., Antagonize, Weapon Finesse). I don't think that's by coincidence.I think it's missing because it was copy and pasted to have this kind of language:
If he already has the Power Attack feat, he can immediately swap it for another feat for which he qualified at the level he chose Power Attack.
It's just that the other talents with that language happened to not have prerequisites.
Derklord, Melkiador,
I agree with your logic. Well-reasoned, well-argued.