Kill an enemy 5 seconds after landing from a base jump.
Complete the optional dialog in Erewhon about your past.
Find  Attachments and then equip one in the gunsmith.
Kill a Breacher, a Rocket Gunner and a Sniper with CQC while in stealth.
Find  Blueprints and then buy 5 Weapons on Demand at Maria's.
Finish SPEAK NO EVIL, HEAR NO EVIL, SEE NO EVIL.
Kill a convoy's driver with a sync shot drone.
Shoot a wasp while it is still on it's carrier's back.
Kill a helicopter's pilot with a sniper rifle or DMR.
Kill an enemy 1 second after another player in Coop has injured him.
Kill 12 enemies without getting detected.
Kill an enemy with a handgun, an assault rifle, a sniper rifle, a DMR, a shotgun, an SMG and an LMG.