Knife an enemy without him ever knowing you were there in Single Player or Special Ops.

Kill 2 enemies with a single bullet in Single Player or Special Ops.

Complete Interval 02

Kill 100 enemies using a dual weapon technique

Defeat the Giant Golem

Throw weapon at enemies 50 times

Finish the game

Obtain the third sword

Kill 300 enemies

Kill 150 enemies

Obtain the Dagger of Time