Preemptive/Surprise linked to an animation or transition?

[KingKraken]

I'm sure this is a lot more simpler than I'm making it out to be but I'm trying to figure out how to make a preemptive or surprise attack, initiate a specific animation or even an image  to alert the player. Say, if you get the preemptive, an image will flash on the screen saying "You have the advantage!" 

But I can't seem to find any conditional branches that refer to that occurrence.I'm not even sure how to make a preemptive action into a variable. Any ideas for either creating a specific transition for each type or separate animation? I'd be fine with something either before the battle, or at the start of the battle. 

Interesting enough, there's two plugins like these which support the concept of the events being based on enemy-player orientation. But I'm not code-savy enough to understand what they do to force the preemptive.