So I have been playing this deck for quite a long time, one of the most consistent Syndicate decks and this season the leader got buffed.
Gameplan is to go Serenity round one with Igor, Candle or even Gellert if needed (Use leader early if required, plenty of coin generation). Then go for a long round 2/3 with rest of the cards. Sometime you will be left with Igor then in that case use him to make copies of the tax collector or mutant in the last round. This deck thins down to 2 cards at the end so pretty good with draws, but you can see in gameplay clip 2, I missed my Salamander still won by a large margin against such a point slam deck, so the deck is not too much dependent on one card. Rayla is such an OP card though.
For alternatives, you can swap out a Tax collector for a Trafficker/Lackey/another Mutant or can even try out Mutant Killer, otherwise the deck is perfectly balanced.
Watch the video for gameplay reference and strategy. Thanks