Thumbs up to Black Sun's Zenith. Great combo with Necroskitter.

I wonder if you're focusing too much on -1/-1 counters. Against a control or creature-light deck, it seems like this would just be... bad. If you don't draw skitter (and with no draw or tutors, it seems fairly likely), you're essentially stuck pecking at them with a couple 1/1 creatures. Granted, infect greatly aids your likelihood of killing them with that, and all the wither or -1/-1 counters will help clear the way for your creatures, but a deck with any sizable amount of control will just completely drain you. I personally think some sort of strategy for maintaining card advantage will be vital for survival against anything but creature-heavy decks (which, of course, this deck will be fantastic against). Whether that means relying on black card draw/tutoring, splashing blue/artifacts, or relying on the green side of things (Aggressive Urge, Life's Legacy, Harmonize, etc) is up to you. Hell, since you sort of want your opponent to be playing creatures so that you can take them, you could even try Rites of Flourishing or something.

That being said, I absolutely love some of the combos here. Virulent Wound seems so bad until you combine it with Necroskitter or Crumbling Ashes.

P.S. I got a Necroskitter in a modern masters pack if you want it. ;)

I don't like Grim Affliction here. I think you could try to run some hand disruption, as it seems that you have plenty of ways to get -1/-1 counters on stuff. What about Thoughtseize or Inquisition of Kozilek? If not main board then definitely sideboard.

Tangle Angler just costs too much. I guess it's a nice defender and you can force them to block it and get a -1/-1 counter, but there are probably better creatures you could run. If you're going for something cheap you could try Ichorclaw Myr or Necropede. Necropede fits in very well with your counter theme.

I think maybe you could also try to add a few pump spells to win out of nowhere. Vines of Vastwood for additional protection or maybe even one or two Become Immense. If you go the Become Immense route you would probably want to run Verdant Catacombs for delve fuel.

I like the deck though! Nice and original.

I think you may want to have Contagion Engine in 1x or 2x

I can't not suggest the Everlasting Torment + Melira, Sylvok Outcast combo to everyone trying to build a wither deck. Especially since you're in the colors. Melira also stops your BSZ from killing your stuff.

Serra_Sentinel: That is so awesome. I've never thought of that combo!

None of your things can be killed by damage :D

Have you thought about some number of Collected Company?

I see your playing Melira, Sylvok Outcast, perhaps Everlasting Torment would work to protect your creatures from damage. Although that might be better in a non-infect list with stuff like Skinrender. I've been trying to figure out how to make a competitive necroskitter deck so I'll be keeping an eye on this, +1.

I really like the idea of this deck. Blowfly Infestation could really ramp things up for you.

Though I don't understand why you have slow cards. The main objective is to throw out quick creatures and reanimate the opponents creatures. So I say this, run Midnight Banshee for late game along with Pharika, God of Affliction so when you steal their creatures, you can then reanimate them AGAIN as deathtouch snakes to kill more creatures.

Really like the idea of this +1