honestly, for only running 21 lands, you look very clogged at the top of your curve. First off you need to hit 5 lands in order to play your slumlords, that's almost 25% of your lands in your deck needing to be on the battlefield. You also have some casting cost that make being able to play those spells consistently when needed very difficult, like Fated Infatuation and Bident of Thassa because you only have 8 total blue sources and one requires triple blue and the other double blue. Those things alone will make your deck very inconsistent and make some games difficult to even play.

As far as suggestions, I'd recommend getting rid of the Rogue's Passage and the guildgates. In place of those you'll want a couple Temple of Deceit and 4x Watery Grave and you'll also want to up your land count to probably 24. I would also get rid of fated infatuation and the bident all together. The triple blue is way to difficult to cast consistently when your only splashing for blue in your mana base and with the bident, I guarantee more often than not when you have the choice you'll be playing the whip or the slumlord before you play the bident. Both those situations will cause you to hold those two cards in your hand longer where they are doing nothing for you so it would make sense to fill those slots in the deck with stuff that can either be more useful or improve consistency. If you find that you need the card draw so you have things to discard to Pack Rat there is an excellent option in black that you could use Underworld Connections it would be much less stressful on your mana base. Quag Sickness is another spell that is just unnecessary. Your better off increasing the number of Hero's Downfall for more unbiased instant speed removal than you are trying to split it like that. Quag Sickness is just unreliable, inconsistent, and being an enchantment it's slower because it can only be played at sorcery speed in comparison to the downfall. I'd also get rid of the Strionic Resonator , I understand its got some cool interactions with Door of Destinies or the slum lord but again its just not necessary and more gimmicky than anything else. Taking those gimmicky elements out will improve consistency in your decks as well. Some may even say Door of Destinies is a little irrelevant in this deck too because in most cases you won't be casting your creatures. Because the door cost 4 by the time it hits the board most likely you'll be discarding your little rats to make bigger Pack Rat copies and that won't trigger its ability to add a counter because your activating an ability not casting a spell. Another thing I would do is cut back on the number of Doom Blade . Not that Doom Blade is bad, but with the number of decks running black right now your just better off using a combination of Ultimate Price , Doom Blade , and Bile Blight or even Devour Flesh as your cheaper removal. I realize you can always discard the Doom Blade to your rats if you run into someone playing black but I just think it would be better to have the option to either use it as removal or to make a rat. I know I've suggested a lot of different things, things that were most likely causing your inconsistency issues, but I've tried not to suggest any cards in the $20-$30 range. I know after taking out everything I suggested and adding in the stuff I recommend your probably still under 60 cards, but I didn't wanna give too many direct swap scenarios because a lot of the stuff I suggested removing was purely for the strain it puts on your mana base to be able to cast them consistently at relevant times. So hopefully you at least have a better understanding of why you were having the problems you were, and that'll help you fill those slots with cards that are more relevant and also help your curve so you that each turn can run smoothly.

Might want to consider something like Annul for the sideboard. Or splashing red or green for artifact hate (Rakdos Charm or Putrefy ) because decks built exclusively around Pack Rat die very quickly to Pithing Needle , which is in most standard sideboards.

I was looking at Temple of Deceit and Watery Grave today and I totally agree with getting rid of Rogue's Passage and the guild gates. I did notice, that the mana feels a bit low, which makes Strionic Resonator makes a perfect candidate for removal. Later scenarios, if they even get that far its proven useful. However, mana has proven to be a problem most of the time. Until I can get some of the cards you suggested I'm going to try and add more lands, and replace Fated Infatuation and two Door of Destinies or maybe all of them, which would also leave me to get rid of the resonators too. Annul was another card I was looking at because it's cheap to cast. I may splash more colors but, I feel more than two colors will make the consistency problem worse than it is. I'll play around with it and let you know what works.Thanks for all the input.

really no matter what deck your playing, if your going to splash for a second color then how color intensive those spells are is important. It's obvious what your trying to do with something like Fated Infatuation in this deck but realistically with only 8 total blue mana sources how likely are you to have 3 of them on the board. Sure it happens but it's just not something you can rely on. Another thing to consider is when you want to be playing that spell. If you want to be able to consistently cast something on turn two or three then you'll have to make sure to include enough copies of that spell so that you see it in your opening hand fairly regularly which means you also have to make sure to include enough of that color in your mana base so that it shows up regularly in your opening hand as well or else you'll end up holding spells in your hand hoping to draw into blue mana. In other words you can't play your blue 3 drop if you almost never see lands that produce blue mana. That last one wasn't really a problem you had with this deck because your blue spells were later in your curve which typically gives you 4 or 5 turns to draw into a blue source before you actually needed it, the problem was even if you did see a blue mana source by turn 4 or 5 you also needed a second or a third which more often than not wouldn't happen.

OK, I dropped the bidents and one Ogre Slumlord because I ran into the scenario you described and it was a painful beating. Trying to figure out a way to protect the Pack Rat s as my roommate always gets rid of them off the bat with his stupid (I'm only hating because I always lose to it) Red win deck. I was thinking about maybe tossing in some Dimir Charm s as to add some counter spells to keep things like Detention Sphere and other spells that instanly kill Pack Rat from being a threat. I've also added another Hero's Downfall and swapped the guildgates and Rogue's Passage with the temples and Watery Grave . I'll give it a couple plays and let you know how it turns out. I refuse to accept rats can't be good in standard like everyone keeps saying.