Successfully complete 100 City Events, Get All Tokens and
Finish All Combat Tours.
Fight Shocker again:
You can see Shocker even after you have defeated him. Sometimes
in a City Event, Shocker will appear and you must fight him. It
will not be a Boss battle, though -- just a fight against a street
thug, who has some very powerful blasters. Note: He is also stronger
than all street thugs.