Mail Slot
ME3: Kill 10 guardians with headshots from the front while their shields are raised.
A Personal Touch
ME3: Modify a weapon.
Driven
ME3: Return to active duty.
No One Left Behind
ME2: Keep your team alive through the suicide mission
Merciless
ME2: Make 20 enemies scream as they fall or are set on fire
Weapon Specialist
ME2: Fully upgrade a weapon
Bruiser
Kill 100 enemies with melee attacks in Mass Effect 1, 2 or 3
Mission Accomplished
ME2: Save humanity throughout the galaxy from certain annihilation
Insanity II
Complete two games in Mass Effect Legendary Edition on Insanity without changing difficulty
Against All Odds
ME2: Survive suicide mission
Suicide Mission
ME2: Use the Omega 4 Relay
Paramour III
Establish or rekindle a romantic relationship in all three games in Mass Effect Legendary Edition
A House Divided
ME2: Hack a geth collective
Friend or Foe
ME2: Obtain geth technology
Scholar
ME2: Unlock 15 new Mass Effect 2 codex entries
Warp Specialist
ME2: Warp the barriers of 25 enemies
Tactician
ME2: Hit 20 different targets with multiple biotic powers to combine the effects
Head Hunter
ME2: Perform 30 headshot kills with any weapon on humanoid targets
Agent
ME2: Complete 5 missions discovered by scanning unexplored worlds
Treason
ME2: Gain the loyalty of the quarian