The Silver Feathers are back in God of War: Ascension and they fulfill the same function that they always have in all the previous God of War games; increasing your magic power.
They are found in white chests and once you’ve collected five feathers your magic gauge increases, allowing you to throw out more spells before running dry. To max out the magic gauge you need to collect a total of 15 feathers.
There are more than that in the game but opening a white chest after maxing out your magic will only award you bonus red orbs. Furthermore, if you manage to collect all 15, you unlock the silver ‘Light as a feather’ trophy.
Thanks. PowerPyx For Video.