Choose to open the sphere in mission 39. The game will blatantly say "do you want to open the sphere or destroy it". It's a typical karma choice as most of the trophies in this game is. Choose the "evil" option and you'll unlock this. Choose the other option and you'll unlock
If you choose this you'll get a lot more damage but be locked into the "infamous" mode for the rest of the game with no chance of going back to good.