User blog comment:Subject 16*/Assassin's Creed: Revelations - News/@comment-3967387-20110505205528

It looks like the hook is attached to the blade, but doesn't replace it. I would imagine it is made from the same metal as the hidden blades, so it'll be really strong. Unless Ezio discovered a stronger metal with a little help from the Apple? And maybe Da Vinci as well?