The easiest way to fix UA, since it's so overwhelming and overpowered at once is simple.
Divide and conquer the damn stat.
Axe it, so it's not the only important stat for combat, for doing and taking damage to the defensive gauge.
Have unarmed skill only affect unarmed combat, like how melee skills affects only melee combat.
By this I mean primary offensive only, and doesn't include defensive. Melee's defensive is only from using a shield.
And then having agility (and constitution) be the basis on bonus defense against strikes.
Strength be the bonus offense.
By dividing and splitting up the functionality of the stats, it means botters will now have to eat, grind, several stuff at once, dividing the speed several times.
So instead of a botter building only int and UA, and abusing the mental inventory mechanic, he'll have to instead grind int for LP, strength for offensive, agility for defensive, and the skills for effectiveness.
Heck, maybe allowing both agility and constitution to provide bonus to defensive stats, will outdo a character that mainly goes for pure one hit kills since buffing two stats to balance is easier than buffing one to a super high level.
It is easier to get to AGI 30 and CON 30, over STR 60. Although beliefs boosts the stats, it'll only be 1.25x offensive compared to a 2x defensive since your being able to use two stats for it.