Prince Ezio is the adopted son of Queen Chrysalis and plays an important role apart of the Imperial Alliance (Equestria, Changeling Hive, Griffon empire, Dragon Kingdom). Most ponies and Changelings like to relax on there spare time, but not Ezio. Instead he prefers to clean the streets of scumbags.
His deeds go unnoticed by the public, but not by the criminals. So when the crime rate goes up, he has a hard time getting the job done, but luckily the vigilante thing is just a hobby. But unfortunately for him, the criminals are the least of his problems. The Paragon Nations (Crystal Empire, Minotaur Union, Sphinx Nation, Centaur Syndicate) continue to attack and terrorize the I.A. So he decides to attack them where it hurts. Their Leaders. And he won't be doing it alone

In an Alternate Universe where Changelings, Ponies and Griffons live together in harmony. King Sombra is still alive and is still an evil ruler of the Crystal Empire, and the Canterlot Invasion never happened.
Definitely based off of Assassin's Creed.