Shay Cormac becomes a Templar after surviving the Lisbon earthquake in Assassin's Creed Rogue.
Shay is initially an Assassin working with Achilles Davenport's Colonial Brotherhood. During a mission to Lisbon, he retrieves a Precursor artifact from beneath the city. The resulting earthquake kills many people, and Shay concludes that the Assassins' pursuit of Pieces of Eden can cause catastrophic harm.
After rejecting Achilles' instructions and leaving the Brotherhood, Shay is taken in by former Assassin hunters associated with the Templars. He eventually joins the Templar Order and hunts his former allies across the North Atlantic and North American colonies.
The Lisbon earthquake is based on the devastating earthquake of 1755, although the game's supernatural explanation is fictional. Rogue therefore presents the unusual perspective of an Assassin protagonist who changes sides.