Complete 300 missions or multiplayer games.
Halo: Reach: Find the hidden binary signature.
Collect 8,000 campaign or playlist medals.
Halo CE: Activate Terminal 1 on The Pillar of Autumn.
H3: ODST: Beat the par score on Tayari Plaza.
Halo 2: Beat the par time on Sacred Icon.
Collect 3,000 campaign or playlist medals.
Complete any co-op level on Heroic difficulty.
Halo 3: Find and claim the Fog Skull.
Halo CE: Complete The Library on Heroic or Legendary difficulty without dying.
Halo 4: Survive Spartan Miller (Ep.5 Ch.1) of Spartan Ops on Heroic or Legendary.