Anarky will be throwing explosive and his henchmen at you before taking you on himself in Batman: Arkham Origins.
Anarky is one of the easiest boss fights to encounter in Batman: Arkham Origins. The only things you have to worry about are his henchmen and his love for explosives.
Anarky carries a disdain for governments and corporations which he believes are rotten. While he may be right in pointing out the corruption of Gotham City, destroying public property and spreading anarchy is not the way to deliver justice.
It would be best if you took Anarky down to end his terrorist activities. Gotham City will not tolerate anarchists on the loose. That includes wiping out his Anarky Tags. How to find Anarky in Batman: Arkham Origins
Anarky is not part of the main storyline. The only way to confront him is to finish his optional Most Wanted mission which requires you to find and disarm three bombs. You, however, will need to defeat Deathstroke beforehand to unlock the side mission.
After completing his side mission, you will discover that Anarky uses an Abandoned Courthouse in the Park Row district as his hideout. Follow the waypoint on your updated map and enter the courthouse from the back to start the boss fight.