[Modern] -1/-1 Extermination

[rspickens]

-1/-1 Extermination

Creature extermination, with a few game winning combos.  This deck has been a work in progress for a while.  At time it moves slow, other times it works, and other times it works to well....well enough to wipe out my creatures.  Could use some advise please.

[entropize]

Well I have a deck with a similar strategy called Touch of Decay. I would suggest reducing hapatra down to two or three since she is a legendary. Some cards to consider are phyrexian crusader, hand of praetors, and doubling season. I would suggest switching 2 blowfly infestation for two crumbling ashes. I would also suggest either reducing the number of lands or mana producers since you have 20 lands and 8 mana producers with most of your cards costing about 2-3 mana to play. I also suggest trading zulaport cutthroat for the quillspike. Some other cards to consider would be voracious, sturdy, and noxious hatchling. If you decide to add doubling season or the hatchling, I also suggest adding melira sylvok outcast since those cards act as a double edged sword.

[entropize]

Whoops, just read the part of doubling season only working cards you control, so forget that suggestion. Mind you it would double the number of arrow counters on serrated arrows as well as the number of tokens produced. I thought it doubled all counters, oh well I guess that would too over powered.

[Odysseus1212]

you definitley need Black Sun's Zenith! Best card in this deck.
I also play Dusk Urchins as carddraw (could work very nicely with your Channeler Initiate). Play Carnifex Demon as an endless -1/-1 counter engine with Blowfly Infestation. The last creature dying lays its counter back on the demon so you can repeat - awesome, you'll love it. Suggest Serrated Biskelion as an alternative card to Serrated Arrows. As fast as the arrows, but lays 4 counters instead of 3, two at a time. Also works better with your Zulaport Cutthroat. Also suggest Putrefy rather than your other two removals.
Quillspike is nice but not needed, since you get profit from every creature that dies with an counter. Don't ever cut Blowfly Infestation, since it's your epic CC card on the battlefield. Crumbling Ashes looks really nice, but shouldn't also be needed if youre flooding the battlefield with your counters. Noxious Hatchling is a nice fatty, but sadly doesn't do anything for your goal.
Also very sadly, your best combo engine of this deck (Nest of Scarabs & Blowfly Infestation) can also be your worst enemy, since it creates an infinite loop, if no creature on the battlefield is stronger than 1/1, because none of the effects is optional.
I also suggested Kulrath Knight, sady its CMC are much too high since you can't be sure it will control all of your opponents creatures.