Cheats
Completing seven game sequences at 100 percent Synch unlocks specific cheats that can alter game play. Beat Sequence 1 and earn the Ride the Unicorn achievement, which turns all horses into unicorns. Beat Sequence 2 and win Buns of Steel, which grants invincibility. Beating Sequence 3 earns the Killing Spree, which makes your assassinations impossible to block. Sequence 4 introduces Sisterhood, making all Assassin's Guild recruits female. Sequence 5 opens the Ultimate Guild, meaning all recruits get Assassin rank. Sequence 6 earns Calling All Assassins, which disable the cool-down timer when calling assassins. Finally, beating Sequence 8 grants Desmond Everywhere, allowing you to play as Desmond Miles, the modern ancestor of the game's ancient assassin.
Capes
Completing tasks also unlocks secret capes for the assassin Ezio. Repairing everything to 100 percent on Rebuilding Rome wins the Auditore Cape. Collecting 100 Borgia Flags earns the Borgia Cape. Finishing the "Auditore Trail" mnemonic set in the Italian Wars segment or playing the "Assassin's Creed: Project Legacy" Facebook game to level 30 wins the Medici Cape and the Venetian Cape.
Rebuilding Rome
Completing specific tasks during the Rebuilding Rome section will earn special rewards. Restoring four tailor shops earns a knife belt upgrade and a medicine pouch upgrade. Restoring five blacksmiths earns the Cavalieri Mace and the Butcher Knife. Restore eight tailor shops and get another knife belt upgrade and a poison vial upgrade. Restoring 10 blacksmiths wins the Spadone Longsword. Finally, respawning the Battle Horse restores all nine stables.
Costumes
Earn a Bronze or better on all Virtual Training Challenges and you'll unlock the Raiden costume, which disguises you as Raiden from the "Metal Gear" video game series. You can also purchase a Florentine Noble Attire, an Altair costume and Altair's Armor for two Uplay tokens each.
Guild Rewards
The game allows you to work with the Assassins Guild, the Courtesans Guild, the Thieves Guild and the Mercenaries Guild, hiring their members to help you complete missions. Each guild house also displays a list of 10 challenges, which, when completed, levels up the guild members and earns you extra rewards. Sample challenges include killing 25 Papal guards, evading 10 enemies and commandeering 10 horses without killing the riders. Finishing five challenges in the Courtesans, Thieves or Mercenaries Guilds earns you the respective guild's crest as a trophy and also provides a 50 percent discount when hiring the guild's member. Completing all 10 Courtesan Guild challenges rewards you with Maria's Dagger. Finishing all 10 Thieves Guild challenges wins the La Volpe's Bite, a special sword. And completing the 10 Mercenaries Guild challenges earns Bartolomeo's Axe. Passing all Guild Challenges earns the Assassin's Guild Crest and the Sword of Altair.