In Assassin's Creed Syndicate, Jacob is the Frye twin who leads the game's London gang operations.
Syndicate, released in 2015, follows the Assassin twins Jacob and Evie Frye in Victorian London. Jacob is the more openly confrontational sibling, and he forms and leads the Rooks, a street gang that challenges Templar control. Evie concentrates more heavily on stealth, investigation, and the search for an Isu-related artifact.
The twins share the campaign but have distinct abilities and missions. Jacob's activities include liberating boroughs, recruiting gang members, and confronting organized crime and Templar influence. The Rooks become a practical network that helps the Fryes move through London and oppose the rival Blighters.
Evie is the likely alternative answer because she is equally playable and is Jacob's twin sister. Henry Green is an Assassin ally and the London bureau leader, while Maxwell Roth leads the Blighters for part of the story. The wording “gang operations” identifies Jacob's role rather than simply asking for either protagonist.