Reach the end of the cliff

Complete 15 Agility or Power Challenges

Kill 100 enemies by kicking them off the rooftops/cliffs.

Kill an enemy with a wrench, using Vault followed by Drop Attack

Finish all side quests

Complete 5 quests in a single co-op game with the same 3 partners

Add a fire elemental effect to a sword or a khopesh

Push the Flut Flut Egg Off the Cliff

Score 10 headshots on Rais's men with a bow

Climb at least 8848 meters on various objects.

Jump to the water from the Infamy Bridge (Slums) at night

Throw 50 enemies with Grapple