Shay Cormac is the protagonist of Assassin's Creed Rogue, which follows his turn against the Assassins.
Shay begins the story as an Assassin operating in the North Atlantic during the Seven Years' War. After a disastrous mission and a crisis of faith, he defects to the Templars and hunts former allies. The game therefore reverses the usual player perspective by making the protagonist a Templar for most of the campaign.
Rogue was released in 2014 for PlayStation 3 and Xbox 360, with later versions for Windows and current-generation consoles. Its naval exploration connects it thematically to Black Flag, while its story leads directly toward the events surrounding Assassin's Creed Unity.
Shay is not Liam O'Brien, although Liam is an important Assassin character and former companion. Adewalé also appears in the wider series but is not Rogue's protagonist.