The Jack The Ripper Add-on for Assassin's Creed Syndicate has 7 achievements worth 300 gamerscore.
Perform 30 complete Brutal Takedowns.
Kill a Brute while he calms down his panicked allies.
Scare an enemy and make him kill someone else by mistake.
Frighten 200 enemies.
Unlock 50% of the skills.
Achieve 100% synchronization in the DLC.