The Dead Kings Add-on for Assassin's Creed Unity has 7 achievements worth 300 gamerscore.
Achieve 100% synchronization in Dead Kings.
Complete the Heist and the Co-op mission in Dead Kings at least once.
Free every outpost in Franciade.
Complete Suger's Legacy and recover the Eagle of Suger.
Complete Memory Sequence 13.
Kill 15 Raider leaders.
Kill 5 enemies at the same time with a Guillotine Gun.