Hey, I don't know if anyone else mentioned this, but Father's Teeth would be an amazing addition to this build.
It is up to RNG as it's only available from an Average Level Caed Nua Adventure, but I think it would be perfect for you!
It's an amulet that grants 4 casts of "Rot Skulls" per level, which summons the wand Rot Skull as the character's primary weapon for an extended period of time, around a minute with good intellect.
The weapon itself does 22-32 Crush damage BASE, along with 52 AOE Corrode damage 1.5m from the target, like a better version of Kalakoth's Minor Blights
This, or a similar summoned wand could be precisely what you're looking for, as it would maximize your fighters high crit potential, while chucking AOE downrange to boot, and it can be used four times per rest, which is generous I'm fairly certain all wands summoned weapons give a significant accuracy bonus as well.
