I haven't been really impressed with Orzhov zombies. I wanted to try going a different route. Maybe this isn't much better than has already been around but it feels better to me. How can I improve this deck?

Deck: Dimir Zombies (Bu)

//Main
3 Aether Hub
2 Compelling Deterrence
2 Diregraf Colossus
2 Distended Mindbender
2 Drowned Catacomb
2 Elder Deep-Fiend
2 Evolving Wilds
1 Gisa and Geralf
3 Glimmer of Genius
3 Grasp of Darkness
3 Haunted Dead
3 Island
1 Kalitas, Traitor of Ghet
1 Liliana, Death's Majesty
1 Liliana, the Last Hope
4 Miasmic Mummy
3 Murder
2 Never // Return //
2 Possessed Skaab
2 Prized Amalgam
2 Scrapheap Scrounger
2 Sunken Hollow
12 Swamp

Display deck statistics

Cut all blue cards other than amalgam and maybe glimmer of genius?
None of them seem strong enough.

I'd cut the Emerge creatures and focus more on zombie tribal. Most of the good/expendable zombies are low cmc so it's still difficult to emerge anything with them.

Possessed Skaab is pretty rubbish at 5cmc with those stats. Getting a spell back isn't terribly important here. Exiled when he dies = bleh.

As Hello World alluded to, I'd make it a mostly black deck with just Amalgam and Gisa/Geralf, and maybe Compelling Deterrence as the blue part.
Dread Wanderer is a new card we got that's great for triggering Amalgam from the GY.

Cryptbreaker is a must in virtually any zombie deck. He's a discard outlet, token spawner AND card draw.

I had been meaning to revisit Dimir zombies anyway, so I just threw this together;

2x Cryptbreaker
2x Dread Wanderer
3x Festering Mummy
4x Miasmic Mummy (or Screeching Skaab, or a combination of both)
2x Diregraf Colossus
2x Prized Amalgam
3x Lord of the Accursed
2x Plague Belcher
1x Kalitas, Traitor of Ghet
1x Gisa and Geralf

1x Smuggler's Copter (we probably want 2 of these actually)

2x Dark Salvation
2x Grasp of Darkness
2x Compelling Deterrence
2x Cemetery Recruitment
2x Never // Return

1x Liliana's Mastery

Liliana, The Last Hope
Liliana, Death's Majesty

11 Swamp
7 Island
2 Drowned Catacomb
2 Sunken Hollow
1 Westvale Abbey
1 Geier Reach Sanitarium

First, it would be a completely different deck and going mono black would be better suited for an agro deck with Bone Picker. Second, the blue adds in a recursive subtheme which is very zombie and which is why I feel it is a little stronger than the white. Card draw is always nice when you are trying to add in a bit of card advantage where you can as well.

I made some changes and am trying out Cryptbreaker. It seems okay so far. I've got some more experimenting to do before settling on a final list. It seems like a tier 3 deck but I feel that way about zombies altogether. If I want to put a beating on someone, I have other decks for that.

If your are throwing cards in the graveyard you should run take inventory instead of Glimmer.

Anyway here's what I'm trying, still rank 20 due to me playing badly, the game crashing mid match at random times and the deck needing some fixes, like making the mana base better.

Creatures

2 Cryptbreaker
2 Dark Salvation
2 From Under the Floorboards
3 Gisa's Bidding
3 Haunted Dead
2 Heir of Falkenrath
1 Jace, Vryn's Prodigy
2 Prized Amalgam
2 Scrapheap Scrounger
2 Smuggler's Copter
2 Wharf Infiltrator
2 Dread Wanderer

Noncreature spells
3 Broken Concentration
3 Fatal Push
1 Glimmer of genius
2 Murder ( no never//return for now)
1 Read the Bones
1 Drake Haven( part of me wants to cut this for almost never triggering tho)

Lands

2 Drowned Catacomb
7 Island
3 Submerged Boneyard
2 Sunken Hollow
8 Swamp
2 Westvale Abbey