Feral Link

The Feral Link (シンクロ・ドライブ), also known as Synchro Drive in Japan, is a gameplay element appearing in Final Fantasy XIII-2. It allows the player to execute any recruited enemy's special attack, thus dealing a significantly larger amount of damage than normal, by correctly performing the necessary actions required by a triggered Cinematic Action.

Mechanics
When the Feral Link gauge fully charges, the player can press on the PS3 controller or  on the Xbox 360 controller to execute enemy's special ability. In IGN's "Quest for Lightning" trailer a new feature is introduced to support Feral Link system under the name "Synchronization". If the Synchronization will be correctly executed, the Feral Link deals larger damage than it normally would.

Trivia

 * Some enemies fighting alongside Serah and Noel have different names than when they are opponents. This may be due to the fact that, as mentioned in the PAX 2011 interview, you could customize these monsters in some way.
 * While performing a Feral Link, a distortion similar to one seen in Final Fantasy XIII during Full ATB Skill execution is featured, although in a different angle.