TheBear

I kinda wanna see the two Common Eldrazi in this, since you can generate a ton of mana.

I would mainboard the Eidolons, they are honestly insane in the Legacy Format. I do like having 2 Price Of Progress, as it can finish someone off out of nowheres. Grim Lavamancer is alright, but not the best, I honestly think just going down to 2 is fine, If you don't like Vexing Devil much you can replace him with Monestary Swiftspears, as they kinda act like extra Goblin Guides. I also believe you can drop down to 19 lands, your curve is extremely low as is, which could make space for maybe 1-2 Searing Blood, which are actually pretty good in legacy.

Perhaps, I've just not been a fan of Bob lately, the big decks nowadays obliterate him.

Since this isn't a legacy version we can't get too many broken interactions, but these are other comments I think.

Dark Confidant, not really needed if you have the Loam Engine going, if you need more draw put in maybe 1-2 Horizon Canopys or Cycle Lands.

I would get a full 4 of Raging Ravine, you need it as a good win con since we don't got Dark Depths combo.

I would cut the Inquisitions and 2 Ravens for 4 Bolt, it's too good in the format to not have currently.

I would also dig around for lands that have alternative abilities, things that can be abused if you can recur them over and over.

I've played a lot with these Loam based decks, you want full 4 Smallpox, it's too good in these decks, and honestly I think you want 4 Bloodghast, since you should be able to get landfall all the time.

This looks like an interesting idea to me, putting together a Rites package in Delver, but I do think some card choices can be better.

Lightning Helix doesn't do much for you in this deck, it's a great card yes, but not for Delver.
The same goes for Lynx, Delver just has way better creatures to pick. I also believe you want to cut down to 2 Geists instead of a full 4.

Now for additions, You will want Young Pyromancer as a 4x, he's insanity in Delver and it's large spell count. In the Spells itself, I think you can get away with only 2 Path To Exiles, and run Gitaxian Probe, 1-2 Treasure Cruise to give you a reload mid-late game. If you do go with Treasure Cruise, I could recommend cutting down on 2 of the Snapcasters to make a bit more space and have them replaced with more cheap spells. (Forked Bolt, more Remands, No.3 Treasure Cruise, etc.)

These are just things that come to my head first, there is obviously things I probably missed that suit the deck better, but these come to my mind at first thought.

Other then the Mana Base, to fit the style of taxing and just keeping your opponent down. Cards like Thoughtseize, Inquisition of Kozilek, Thalia, Guardian of Thraben, Gaddock Teeg, Scavenging Ooze, Spirit of the Labyrinth, Maelstrom Pulse.
And for just the ultimate game enders, things like Knight Of The Reliquary, Tarmogoyf (If you are willing to go that far on the budget), Elspeth, Knight-Errant seems more appropriate then Sorin, as she alone will win games, while Sorin not as much.

Seems like an alright start, is this more focused on casual or something you want to go full competitive with? It'll help for suggestions.

To make this work, I think you need to look up some of the Merfolk decks for a start on a tribal deck in modern.

To me, this deck feels like it wants Aethervial as a way to cheat in Goblins, also more Lords to give the team a pump instead of using Obelisk, unless there isn't any more, then my bad.

I also would think maybe splashing in Black or Green to get some of the weirder goblins from Shadowmoor and Eventide etc, which open you up to a better card pool to build with.

I feel like the Swiftspear and Daxos are a little out of place in this deck, which feels like it's closer to control/midrange of all things.

If you take those 6 out, And the two Vyages End, which gives you 8 spots.

You'll want I think... 25 lands for this, Keranos/Narset/Sphinx are expensive and you always want the land drops.
2 more Mantis feels good, as they pressure Planeswalkers really well.

Last 3 slots I think are suited to another Dissolve, and perhaps two End Hostilities, since you may move towards a more control feel.

It'll make the deck closer to something like a Control/Burn deck, which I think could be pretty good.

I actually like how this deck looks quite a bit, but I think I can recommend some upgrades.

First, the land base, Temple Of Silence and The W/B Pain Land will help fix mana a lot, this deck could even run a few of the Fetches to filter up your deck.

Second, I think you should cut the Read The Bones. And put in an extra Return to the Ranks, and probably 3 Thoughtsieze.

And personally I think Mardu Hateblade is just not enough for standard play, I would recommend Tormented Hero, as he is a warrior and just has more use.

Alright, so seeing the sideboard, I see one BIG thing, Blood Moon.
Now, I know it's very powerful, but you are playing 3 colors, it could turn into a major double edged sword here.

You could probably use those 3 spots for some Combo hate, such as Surgical Extraction.

Since you are in the colors and have the Angels, ever thought of having Kiki-Jiki and having access to the combo?

The deck looks pretty solid, but I do have some things I think that should be changed.

First, I don't think Batterskull is what you want here, 5 mana for a Delver deck is a lot. The story is similar with Tombstalker, but he's got some wiggle room due to having Delve. If you decide to remove those 3, I would put in Dark Confidant, you're low mana curve will do wonders with him.

Second, Dismember is good, but it's better Sideboard for match ups with big creatures. Having an extra Remand and Electrolyze would suit you better.

Since you have no Sideboard, extra spot removal, some gravehate, Spellskite or two.

And we have a winner.

I don't deny it's power, I use to run it in Legacy. I just don't think 4 Raven's is the right number. Especially with other more powerful discard/disruption, like Smallpox which counts both as Removal and Hand Disruption. But I have seen Pack Rat in some lists go nicely, same with Tombstalker and Nyxathid (I believe that is how it is spelt) if creatures are what you want. But if you do go creature idea then Smallpox is less valuable.

You have access to five colors, you will more then likely have an answer in some shape or form. Counter magic, Exile, -X, -X

Then play Child Of Alara, Slivers main enemy are board wipes.

I agree with VintageFTW here, Instead of having all this extra removal. You should be running these, at the least.
4 Inquisition Of Kozilek
4 Liliana of the Veil
4 Wrench Mind
4 Smallpox.

Things to cut would be Mindrot, Duress, I'd say 2-3 of the Raven's Crime. Majority of the removal isn't needed. Damnation is better then any removal in this kind of deck.

Also, Ensnaring Bridge is what you would want to deal with creatures anyways. Why care about killing them if they can't even attack.

More lands should be used also. 4 Mutavaults with 1-2 Urborg are good with about 17 swamps included.