How do you set up counter-attacks?

I'd like that if an enemy targets a specific character under a "counter" status this character attacks back or applies an effect against the enemy. I'd also like to redirect all enemy attacks to that character.

There's a way to reprogram where a skill will land, but it's only effective during the character's turn, not during the enemies' turn which's what I want.

The limited documentation on technical parts of the engine like the syntax used by the formulas makes me wonder if it's even possible. I only learned just today that I could use "damage / 2" to halves damage dealt of an attack instead of doing something like "u.atk / 2".

It's kinda complicated, that would require using a plugin directly if you don't want the effects code to look ugly for every skill. I could help on developing it if you have some issues while doing it.