During the Omnic Crisis, Titans were weaponized into war capable variants of the original design and used against humans. They are described as walking skyscrapers and possess powerful weaponry such as energy cannons in place of hands, a rocket launcher on it's shoulder and gatling guns on it's sides, their external hull also possess a heat sensor. The omnics also installed drones into the Titans to act as an internal defense system. These Omnics were seen in flashbacks of the "Are You With Us?" and "The Last Bastion" cinematics.
In "Destroyer", Sven piloted yet another version of the Titan: a retrofitted Titan he developed - which possessed a lot of additions to it (including massive shoulder cannons), with many of the original specs changed up - to attack the city of Boklovo. The Titan's internal drones were also upgraded by microthrusters. He was stopped by Torbjörn. This Titan variant was not an omnic, but rather a vehicle.