A huge hammer
collect them in all the cities.........ps----easy
Assassin's Creed 3 hasn't come out yet, but in Assassin's creed Brotherhood you get the "In Memoriam" trophy or achievement.
Collect 50 feathers, and the last weapon, a new warhammer, will be available in the Monteriggioni blacksmith.
it is the condottiero hammer. you unlock it when you have put 50 feathers in the chest in maria's room in the Villa Auditore
After 50 feathers you receive a special weapon.
How do you get all the feathers in the assassins creed game.
By solving the glyph.
50
When you collect them all, take them to your mother. She, then will make you a something special. (I know what it is, I just won't give anymore spoilers.)
if u collect them all you get money
You play the game!
unlock certain achievements