https://deckbox.org/sets/632414

I've been tweaking on this deck for a while and it just seems to be missing something. It never quite performs up to my expectations, so I'm looking for some opinions. I want to stay in the theme of using my opponents deck against them. I don't expect it to win at FNM, but I'd like to have a decent showing. Any advice would be appreciated.

If this is a deck idea I should abandon in standard I guess I'd like to know that as well, but be gentle. :)

Thanks in advance for your input.

The creature stealing idea is pretty bad.

1) your opponent has to play creatures, not all do.

2)the creatures have to be of sufficient value to both hurt your opponent and help you, which means small aggressive creatures are bad for you to steal it has to be something big.

3) most of your creature steals are conditional and expensive.. if they don't play the right creature or can answer your spell, then you invested a lot of mana for nothing

you've got a set of thoughtseize, hero's downfall, nightveil specter and 3 mutavaults showing in your inventory. If this is correct I can't imagine a scenario where a black deck wouldn't want all of these. You're far better off playing a mono black deck splash blue if you want to run some of these things. The half baked discard plan isn't going to help very much if they start landing threats you can't answer.

Thanks for your input. I had kind of come to some of the same conclusions. So here is a Dimir deck I've been working on instead.
https://deckbox.org/sets/718662

I don't have pack rat and don't really want them. Other than that I'm open to any other idea.

Better imo, but drainpipe vermin and both sirens. Should probably be something else. The brain maggot is okay. I get not wanting to pick up packrat at this time. It is a good card though.

Here's my reasoning. Controlling siren is too expensive to be useful and discarding siren competes with ashiok, master of the feast, and night veil as a 3 drop (not to mention downfall which is a must include) which means if you have one of them you probably won't be casting the sirens. Also, flying gives them a slight edge , but the 1 health just doesn't cut it.

dissolve is not where you want to be in this type of deck. Some hard removal like doomblade/ultimate price would be much more useful.

I think 2-4 gary would be good. you have enough black permanets to support him.