Get cheats by getting 100% synchronization in certain sequences. These can only be used while replaying memories with the exception of the Desmond Outfit.

Unlockable	How to Unlock
Buns of Steel	Get 100% sync in Sequence 2.
Desmond Outfit	Get 100% sync in Sequence 8.
Killing Spree	Get 100% sync in Sequence 3.
Ride the Unicorn	Get 100% sync in Sequence 1.
Sisterhood	Get 100% sync in Sequence 4.
Ultimate Guild	Get 100% sync in Sequence 5.
Unlimited Assassin Signals	Get 100% sync in Sequence 6.