This is a new one. I don't know exactly how competitive Standard leagues are on MTGO right now, though this list certainly has my attention. Today's deck is a Radkos Rock style deck, that in many ways plays like a Jund deck despite sticking to two colors. I don't know if I can endorse every card slot, though the only reason I'm aware of this deck is because it did 5-0 a league.
This is the first Sin Prodder deck that I've seen, and it has the type of spells that you want to pair with the card. When you're flipping four, five, and six mana spells your opponent won't want you to draw them, and by binning them they risk dying to Sin Prodder damage. There are no shortage of lands for the Prodder to whiff with, though this can help enable delirium for Mindwrack Demon. It seems like given the decks reasonable ability to enable delirium that To the Slaughter should be somewhere in the 75, though maybe it's unnecessary.
What this deck boils down to more than anything, is a supporting cast for Goblin Dark-Dwellers and Chandra, Flamecaller. You can theoretically win games just on the back of Prodder and Demon beats, though mostly the game plan is to try to wear your opponent down as you build towards your big finishers. There's a nice mix of options for the Dwellers to flashback, and the Mindwrack Demons will "enable" them by milling random spells to flashback. I find it curious that there is only one Kolaghan's Command, as that card generates absurd value with Dark-Dwellers, though it's possible that nobody is going big enough that you need to go super deep on this level of recursion. It's also true that there aren't really artifacts that you want to Shatter, and a Shock is only so desirable.
I think I'd like this deck more if the Prodders were removed entirely and the deck just featured more Languish. Standard is looking for a Languish deck right now, and if there's a good Mindwrack Demon shell then that sounds like a perfect home. The current list only plays one because it's too heavy on things that die to it, and I'm not convinced that Sin Prodder is anywhere close to worth this concession- especially with Human Aggro being the best or second best deck in Standard.
5-0ing a league is far from a given, though I don't think this deck is there just yet. A deck with many of the same spells could see PT success this weekend, though I'd expect such a list to be heavier on Languish and K-Command and to cut Prodders. I fully expect evolutions of this list to be viable in Standard though.