This deck is built to utilize -1/-1 counters as effectively as possible. Traditionally, -1/-1 counters are used to weaken and kill creatures. While that's swell, there's so much more you can do with them. In this deck, placing -1/-1 counters allows me to generate an endless amount of creature tokens, combo off to drain all opponents of their life, and even wipe their creatures and take them for myself.
The Win Condition
The general idea is to abuse the placement of -1/-1 counters. This is most easily achieved by using Devoted Druid and Quillspike. Together, they will allow you to place a -1/-1 counter as many times as you like. This could result in a massive token army with Hapatra, Vizier of Poisons or Nest of Scarabs. Alternatively, Obelisk Spider in combination with Devoted Druid and Quillspike will drain our opponents life completely.
Removal
This deck does not have a lot of removal, as I generally prefer leave targets available to place -1/-1 counters on. Still, I feel it's important to run Murder in the event I can't place the -1/-1 counters quick enough. Naturalize is almost always an inclusion in any deck with green in it for me. Scar and black sun zenith serve as pseudo removal, but are ultimately in the deck to exploit the effects of placing counters.
Support
The creature support I have is in the form of Phyrexian Crusader and Necroskitter. For the most part, these cards serve as a deterrent. Swinging into either of these cards just allows the placement of -1/-1 counters, and you'll have to have some relative beef to get either of those cards out of the way. With Necroskitter, you also have the potential to take your opponent's non-token creatures.
Blowfly Infestation helps keep -1/-1 counters on the board. It's a nice piece that keeps the engine going. Scarscale Ritual also helps put counters out, but also allows you to draw cards. It's not much, but it's helpful.
Contagion Clasp is currently okay and is the most likely to be a dead draw in this deck. I like the ability to possibly dump mana into it if I don't have anything better going on, but the fact of the matter is is that I likely do have something better going on.
Weaknesses
I haven't played this deck very much, as it's my newest creation. Right now, it does suffer from a lack of life gain and it doesn't stand up well to early aggression in the early game. Having Devoted Druid and Quillspike make the deck go very quickly, so it can feel slow when you don't have them.
