Assassin's Creed takes takes place during the present and past, with an on-going battle between two main factions (The Assassins and The Templars). The main focus throughout the plot is to recover the pieces of Eden (Powerful artefacts created by the Isu). Watch Dogs is canonically confirmed to be a part of the Assassin's Creed universe.
Powers of the Verse
Those that share linage to Adam and Eve have enhanced senses (Eagle Vision) which allows them to see the world differently. The present day technology has some futuristic technology (Like the Animus). The past primarily focuses on Assassins who are highly skilled and have access to gadgets, weapons, and vehicles from each respective era.
Robert de Sablé