Batman: Arkham City Perfect Freeflow 2.0 Trophy Achievement Guide
For this trophy you will need to incorporate EVERY one of Batman's combat moves in a single combo. At the end of the round you are going for this trophy, should get a combo of x12 as your Perfect Freeflow Bonus.

There is a total of 13 combos you have to perform!

1 - Standard Strike - PS3: Square I Xbox 360: X
2 - Stun - PS3: Circle I Xbox 360: B
3 - Evade Jump - PS3: X I Xbox 360: A
4 - Counter - PS3: Trianlge I Xbox 360: Y
5 - Special Combo Takedown - PS3: Trianlge+Circle I Xbox 360: Y+B
6 - Special Combo Bat Swarm - PS3: Square+X I Xbox 360: X+A
7 - Special Combo Disarm And Destroy - PS3: Triangle+Square I Xbox 360: Y+X
8 - Special Combo Multi Ground Takedown - PS3: Circle+X I Xbox 360: B+A
9 - Aerial Attack - PS3: Circle, Left Stick+X, X I Xbox 360: X, Left Stick+A, A
10 - Beat Down Finisher - PS3: Circle, Square (8 times) I Xbox 360: B, X (8 times)
11 - Batclaw Slam - PS3: L1+Trianlge, Square I Xbox 360: LB+Y, X
12 - Ultiamte Stun - PS3: Circle, Circle, Circle I Xbox 360: B, B, B
13 - Ground Pound - PS3: R2+Triangle I Xbox 360: RT+Y

It is highly recommended to buy all of the Combat Upgrades before doing this. You will be able to perform Special Attacks after 5 hits instead of 8. Make sure that you do everything in one single combo (your combo multiplies in the top left corner may not break).
Challenge Map: Survival of the Fittest (Extreme) - Round 3