Mr. Freeze

Mr. Freeze is the third boss faced in Batman: Arkham City, and is remarked as one of the most creative bosses in recent memory.

Description
Mr. Freeze's boss, taking place in the frozen GCPD atrium, is a forced stealth section, as Mr. Freeze is utterly invincible to any direct attacks and almost instantly kills Batman by shredding him in half with his Freeze Gun. The acclaim of this battle comes from the fact that Freeze adapts to the player's attacks, so they cannot attack him the same way twice.