My plan was to update shortly, but guess what? I can't get another shiny pip hematite, no matter how much I farm. I've concentrated on Bort Shadowmane as he is easy for me to solo and take no more than 5 minutes a kill, but I've done several other boss fights, solo or otherwise, and I've come up empty. It's a bit hard to give an honest assessment of this build's viability when I can't come up with the shadow pip generation to power it.
That fact in itself (it's hard to get these gems), should be enough to show that the build isn't that viable, at least not for the non-hardcore farmers who play the game. Maybe if you get lucky, you could try your hand at making this build.
I'm currently torn on what to do if I ever do get a second shiny pip hematite (the jewel that gives +3% chance to get a shadow pip). Do I use it on a strong athame that has only one triangle socket? Or do I hold out for a third jewel to put into my double triangle socket athame? Since these are so hard to come by, it would seem a waste to put them into an athame I would otherwise not use.
An athame like Edge of the Raging Daystar gives good health, 16% universal damage, and a couple circle sockets which can be used to up shadow critical chance.
Tamauji's Discerning Dagger only gives a boost to mana and power pip chance, neither of which is useful for the shadow creature build.
I think to make the build the best it could be, you would use Tamauji's Discerning Dagger. But if you wanted to to keep the jewels for your regular gear, you'd put it on a better athame. The shadow pip chance, I think, is more important than the boost to the damage that the athame would give. I am definitely NOT going to try to get four of these jewels just to run the numbers to test which does more damage over the long haul. In theory, though the universal damage boost would do more damage per actual hit, if you get consistently more hits with the other athame, that wins out in damage over the long haul.