This is a deck based around forcing creatures to attack into Souls of the Faultless, and reaping the rewards, with a backup plan in the form of Shadow Lance and fliers. I typically play against a deck  filled with monstrous flying red/blue creatures which my opponent gets into play early with Quicksilver Amulet and keeps in play with Counterspells and the like. He also has a soft spot for Control Magic, but that is neither here nor there. Right now my deck is a bit over 60 cards, as I just started sticking cool stuff in there. It needs some pruning and perhaps some new ideas.

Creatures: 16

Mourning Thrull x2
Souls of the Faultless x4
Blind hunter x4
Sengir Vampire x2
Agent of Masks x1
Oracle En-Vec x1
Mirri the Cursed x 1
Sleeper Agent x1

Enchantments: 15

Shadow Lance x2
Festering Wound x2
Insubordination x1
Pillory of the Sleepless x4
Hissing Miasma x2
Pursuit of Knowledge x2
Greed x1
Debtor's Knell x1

Instants/Sorceries: 3

Castigate x3

Other: 2

Bullwhip x2

Lands: 25

Swamp x12
Plains x12

Total: 60

Basic plan is to get some Souls out there early and clog up the ground. Enemy fliers and other things the Souls can't block hopefully get Pilloried or have already been Castigated. Insubordinations on their creatures translate into two damage per turn, since no one is crazy enough to attack into Souls of the Faultless.  Festering Wound just seems to fit the mood of the deck, especially if it's on a creature who has been Pilloried. Agent of Masks is another slow drain on the opponent. These cards make up the core of the strategy. Bonus fun in the form of Hissing Miasma. Debtor's Knell is just pretty sweet.

The Thrulls and Blind Hunters are sort of just fodder to throw in front of enemy fliers, supply me with a little extra life, and maybe get a Shadow Lance someday.

Greed is like a poor man's Necropotence..this and Pursuit of Knowledge were the only things I could come up with for some card draw. I figured that with the way I will have slowed the game down I can afford to skip a draw for three turns. Long term investment!

What I'm looking for is better (more efficient, perhaps?) creature ideas. Mine are generally overcosted and/or random. Also, if there are other means of forcing creatures to attack that would fit, I'd be interested in hearing them. Should I put in all four Bullwhip?

Any ideas are appreciated.

First, we need to make sure you can efficietly force the attacks that you want to force.  Oracle en-Vec wins the prize for most needlessly complicated mechanic, but it lets your opponent choose which creatures are going to attack.  Knowing about that in advance is nice, but you want to be able to exert more control than that.  In place of the Oracle, try Walking Desecration (and hope your opponent isn't playing tribal, or you may be demanding an alpha strike you can't handle).  Also in the "you attack now" vein is Imp's Taunt, which gets very insidious once you get to the point where you can buy it back.  And in answer to your question, I do indeed think Bullwhip is worth a four-of.  It's not only an attack-forcer, it's a way to kill off annoying X/1's.  Especially if they have tap abilities that let them skip out on their obligations to smash themselves into your Souls.

Finally, there's one card that REALLY turns your opponent's creature's attack against its owner: Enslave!  Your opponent will be really sorry to see his creature attack, because it'll be attacking HIM!  AND it will deal 1 damage to him during your upkeep.  It's everything you're trying to do!