Should I sell this sword, or turn it into a Grand Faust and sell it, keep it for my own use, or change the UV till I get something like Attack Speed Increased: Low and keep it for my own use? Thanks.
Faust UV Bonus Vs Fiend Very High
You could try selling it to the silly masses on the auction house. Otherwise, I'd reroll it.
You'd probably be doing something around normal damage to Fiends with that UV (remember, Faust and Gran Faust do split normal/shadow). I'd keep it, but if you're feeling lucky, try rolling form something better.
I'm sorry for your loss.
You could be sneaky and sell it to someone who doesn't know better, but that's just cruel :) Best bet is to just upgrade to Gran Faust and uncheck the "transfer UV" option in hopes of something better.
A VH damage bonus isn't sufficient to offset the damage penalty. Based on the wiki's damage data for D14:
Weak Hit = 64 (or 50 normal damage + 14 shadow damage)
Neutral Hit = 100
Strong Hit = 130
Add in a VH bonus (4 * 7.5% = 30% increase) and the half normal/half shadow and you get:
65 Normal/18 Shadow = 83 damage or 83% lower than neutral and 63% lower than strong.
So even with VH bonus you are better off hitting the Fiend with an Avenger and will do much better damage with something like a Grand Flourish.
It's useless. Fiends resist shadow damage so you still wont do much damage. Change the UV