QUICK ANSWER
The base game has eight collectible Blades. A ninth Hero's Blade comes from the preorder bonus, but it is not needed for the all-Blades trophy.
Eight required, one optional
PowerPyx lists eight Blades found through the game and a ninth DLC weapon from the preorder Heritage Pack. Plunderer requires the eight base-game Blades; the DLC weapon is not part of that trophy condition.
Blade progress appears on the profile and Chapter Select trackers. Missed weapons can be recovered after the story.
Why collect them beyond the trophy
Blades are usable weapons, not menu-only lore. Finding them expands the combat options behind the Adaptable trophy and lets you match weapon feel to parry, stagger and crowd-control situations.
The preorder Minoan Sword or Hero's Blade name may be presented differently across official and trophy-guide contexts; rely on the pack listing for entitlement and the in-game menu for the owned item.
Quick player questions
Do I need the preorder Blade for Platinum?
No. The ninth DLC Blade is not required for Plunderer or Platinum.
Can I replay for missed Blades?
Yes. Base-game Blades remain available in Chapter Select.
Sources
Primary game pages and specialist guides used for the facts on this page.
Focus EntertainmentStory trailer and exclusive contentPowerPyxTrophy guide and roadmapPowerPyxAll Blade locations