Honestly, considering 99,99999999999999999999% of players just play my games for story/romances, I think current system is fine.
This was pretty offputting, which is why I haven't replied till now.
Firstly, yeah I had some ideas. For example you could make a skill deal your attack score's worth of damage and ignore defense. So if you have 10 attack 10 crit and target has 40 defense, a basic attack would deal 2.5 damage but with this skill you'd deal 10. Every other idea follows this theme really; making some skills use only attack or crit so that while balancing them might be optimal for general damage, gravitating towards one grants utility, survivability and/or very niche forms of damage. This very choice exists right now with Distracting Blows, and I keep envisioning I will favor attack a little for my Thalia just to pimp that skill up.
I have a concern or two about this avoidance mechanic, primarily I think the game loses some simplicity if mobs suddenly have a stat that isn't derived from attributes and that the sisters cannot get. But maybe they can, I'll wait till you explain it in full.
If at first try it doesn't explode, it ain't Jack who wrote the code.