I finally managed to get the functionality into place to allow an ability to properly transform an attack and then repurpose that outcome!
I've been at this for hours now, so let me translate into something more human.
You can now use an ability, that will target the enemy's Action or Mana pools rather than just their health, and when you do this, the code actually handles everything properly. If it's an AOE, the modified stats will be applied, and at the end of that, if there's still the original attack to use (that'll depend on the ability you're using) then it gets thrown out to be dealt with as well.
It still feels like I am trudging through basic RPG interactions here, and it really feels like at times, that's taking much longer than it should, but with every bit of functionality done, it's closer and closer.
I'll take that for a win tonight.