Yeah, you can use ANYTHING you can think of to achieve the goal as long as it abides by the rules. Character specific is one of the easy things to abuse. If you find some bug you can abuse that's also allowable.
Remember for EX setups, the EX flash must occur while the hit counter is present on screen. Preset EX Aoko dumbass orbs would not count whereas a combo like 2c3c214c would count it as it's used when the counter is counting.