User blog comment:Tmntshocker/Hardest Arkham boss Battle/@comment-27663651-20160123210721

Arkham Asylum: Poison Ivy/Titan Joker (Same Difficulty To Me)

Arkham City: Mr. Freeze/Steel Mill Joker (Both In New Game Plus)

Arkham Origins: Deathstroke/TN-1 Bane/Firefly (Both In New Game Plus)

Arkham Knight: Riddler Mech/Drill Machine Arkham Knight (Both In New Game Plus)