This looks significantly improved, but you can still tinker with it a bit here and there. Zombie Master works well with the Nested Ghouls and Zuran Spellcaster, as you don't care if you kill the Nested, since you can just regenerate it.
I would suggest taking Skaab Goliath out in exchange for another Zuran and Endless Ranks. Consider the casting cost of six for the Goliath, sure it gives you a 6/9 creature, but what does that really accomplish? The real strength of the deck from what I can see is the ability to produce a LOT of zombies (mostly tokens) and then fling them at your opponent with no regard for whether they live or die because you have Diregraf Captain on the battlefield. To that end, the only thing you would need the Goliath for is to deal with trample, as you're not looking to overpower their defenses as much as you're trying to overwhelm them.
I would again suggest changing out Reap the Seagraf with Moan of the Unhallowed, but you should playtest to see how things work out on that front. I prefer the deck being a touch slower with Moan because it gives you two zombies instead of one, especially with Endless Ranks of the Undead, that can be the difference between getting enough zombies to overwhelm them and coming up one attacker short.
Have you considered picking up Undead Warchief? Not necessary by any means but he can help speed up the deck and pumps up the zombies in the process. I don't think they're that expensive if you shop around on TGC.
Three more thoughts.
First, many of the non-basic lands you're using really just aren't worth it. Sure they have a few quirks here or there that could be of use, but for the most part, putting a land into play tapped is a MAJOR pain that can screw up the flow of a deck. You don't want to find yourself spending more than one turn where you're not putting more zombies into play, otherwise you'll likely come up short (unless they take that turn off too). Second, given the importance of getting the Diregraf Captains out, you would benefit from some more islands or some additional dual lands (I know they're not cheap, so changing the non-basics out for islands might be your best bet). To this end, I ran four hand simulations and in two of them I was stuck needing blue mana with none in sight. Lastly, I can see where Divination could come in handy, but realistically, this deck doesn't have any mana ramping and is unlikely to be putting more than one or two cards out a turn until relatively late in the game. If you're worried about getting decked, you can spend about $3 and pick up a Howling Mine and then offset whatever speed you're adding to the opponent with Rooftop Storm as your trump card.
I'll leave it up to you to playtest and see what works best for you. I hope these help.