Game doesn't have much to do with Assassin's Creed in themes or feel, but it is absolutely amazing, and if Syndicate let you down in terms of its atmospheres, moods and aesthetics, I highly recommend Vampyr for that foggy, haunted gothic Victorian London vibe. I deeply enjoyed this game and I just started it back up again to play with some different skills. It's a AA, medium-budget production from the Life is Strange people, but the two games couldn't be more different, other than the dialogue options and detective work you do between exploring the city and fighting. Here's a clip of Bloodspear, one of the starter Aggressive Skills Jonathan Reid has access to.
And the Wiki Entry on it. I wrote the ENTIRE Strategy section, complete with the clip!
https://vampyr.gamepedia.com/Bloodspear