Messing around today with button combinations and apparently each character has a back attack which is performed simply by hitting back and attack within a few frames of each other. Percival's is particularly good and I've been rerouting some of the levels to see where this tech can be used. For some enemies you can combo back attack -> heavy which saves time over heavy -> heavy. :)

Below is my current level 2 PB after about a week of running utilizing some Back Attack Tech (1:24 IGT)