You are heading in the right direction by making this decklist, but I have this to say:

Just reading your comments on your other 80-card deck, you have a bad mindset that you need to get over. Running a huge deck so that you don't get milled isn't a good idea. Also you need to realize that there are cards that are good and cards that are bad. Figure out the worst cards and get rid of those. Trim your main deck down to 60 cards, then create a sideboard of 15 cards that you can swap from between games.

Have you ever been saying to yourself "If I can just draw (card) I've got this in the bag." Those are the cards you need to run more copies of.

Have you ever drawn a card and said to yourself "Ah, crap." Those are the cards you need to cut entirely.

20 is too little land, I say go to 24.

With Hedron Crab I'd suggest running 4 Evolving Wilds or Terramorphic Expanse (not both) since it will occasionally let you trigger your crabs twice in one turn.

I am against Deprive, it has synergy with your Crabs but setting yourself back a land drop hurts, since this is a casual deck just run Counterspell - it's the same cost and doesn't make you bounce a land.

Mind grind is awful, especially with so few lands. You'll never be casting it for anything over 2 or 3. It isn't worth it.

Time Ebb synergizes well with mill, I'd run 3-4 of that or Griptide (not both).

A last word of advice. Even though I have made suggestions to try and help you, you must realize the following truth:

Mill is at its best a very mediocre strategy, and most times it's downright bad. You are attacking your opponent's most plentiful resource, and in fact some decks are getting help from you as you do so (I play Manaless Dredge in Legacy; if you mill me for 8-10 cards I will say 'Thanks' as I promptly win the game on my next turn).

It's fun in a strictly casual sense, but in the end other strategies are miles ahead.

I love your suggestions. You are by far a superior deckling than I am. I should've thought about the whole mind grind situation.. but I've already paid for that 80 card deck.. I dont have Halimar Depths Dimir Guildgate Ashiok, Nightmare Weaver Nemesis of Reason or Mana Short which is a HUGE slip up on my side.. I basically invested $50 dollars into a waste of time.. I think if I were to put these 2 decks against each other this deck would come out on top 3/4 times... It may not seem like it but I really do appreciate all the support you've already given a few of my decks and the criticism on them. It teaches me to not pick what I want just cause i think its cool, it teaches me to use what will work best and bring me out on top. If possible tell me any suggestions you recommend. And also, i was thinking of putting 1 or 2 Mutavault s in my deck. what do you think?

I'd drop traum for another Jace good sir. I'm not a fan of cutmpurse and would rather Jace's Phantasm . Up to you though!
+1

emask I think Jace's Phantasm is a nice card but it doesnt really fit in this deck. Its only good ability is that it's a 5/5 flying. I try to keep only creatures with good mill abilities. Thats why i have Dimir Cutpurse I got rid of Ghastlord of Fugue but it's in my maybeboard.. I'm still trying to keep it's main goal in mill. I was also contemplating putting in Aqueous Form for my Cutpurse and Mirko Vosk, Mind Drinker

Mutavault is no good in this deck. You'd be splitting your win conditions. With mill you pretty much have to go all in.

If you want nifty land that will help you mill, run 2-3 Nephalia Drownyard . It's reliable repeatable mill that doesn't take up a spell slot in your deck. Much better than mutavault for you. Far cheaper to buy as well.

It's entirely possible to hang back and control the opponent's board while you slowly and inevitably mill them to death with Drownyards.

What do you recommend I take out in place of Nephalia Drownyard ?

Why are you running 3 Counterspell and 1 Deprive ?

Counterspell is just a quick counter. Deprive i only need one really. I dont want to have to bring in a land unless i had a Hedron out. Vito1014