What's the work
The Sly Cooper franchise follows Sly and his gang performing heist around the world. In the first game, The Cooper Gang fight of a gang called the Fiendish Five (lead by Clockwerk) who murdered Sly's family and stole their precious book The Thievius Raccoounus (aka the Thingus Rakomagoukous)
Who is he? What has he done?
Clockwerk is the main antagonist of Sly Cooper and the Thievius Raccoonus (Sly Raccoon in Europe) and the arch nemesis to the Cooper family. For centuries Clockwerk had a deep hatred for the Cooper family and one day hoped to destroy them and seize their book. When Sly was a child he did so, murdering his family except for Sly himself, during Sly's battle against Clockwerk is asks him why did he let him live when he stole The Thievius Raccoonous and Clockwerk applies 'Because I wanted to show the world that without our precious book, the Cooper line is nothing'. Throughout the game Sly takes out each member of the Fiendish Five one by one and when he finally gets to Clockwerk's lair, he kidnaps Sly's crush Carmelita and uses her as a trap, when Sly releases her he locks up the chamber and attempts to kill him with gas, but with the help of Bentley, Sly is able to escape and and reaches Clockwerk after an intense battle, Sly finally defeats him.
In Sly 2, Sly Cooper and his gang try to steal the Clockwerk parts to make sure he never ever comes back. In the final chapter Arpeggio takes all the parts and attempts to revive the evil bird, but Neyla takes Clockwerk and becomes part of Clockwerk (now Clock-La). After defeating Clockwerk (leaving Bently maimed) and destroying the HATE chip (the essential piece to Clockwerk) he is now gone forever.
In Sly Cooper: Thieves in Time, Clockwerk can be seen spying from a distance.
Freudian Excuse/Mitigating Factors
As is obviously seems, Clockwerk's motive is purely based on hatred fot the Coopers, as he says himself 'I kept myself alive for hundreds of years on a steady diet of jealousy of hate, awaiting the day I finally eclipse your family's thieving reputation'. Their dosen't seem to be any tragic backstory or justifiable motives to him. Has no redeeming qualities whatsoever. Just wants to destroy the Cooper family based on jealousy and hate.
Clockwerk is easily the most evil villain in the Sly Cooper franchise. Most villains in the series are just trying to get money and a lot of them are very comical but Clockwerk is just a sadistic and heartless tyrant hellbent on killing an entire family and wanting to become the only master thief in the world.
Yes, Pure Evil