4 Snapcaster Mages. There's really no reason to run less.

I'll buy that.

i think 1x Sword of Light and Shadow might be good in sideboard or even main board. having life gain plus being able to return creatures to your hand from the yard is pretty beast.

Lifegain would be nice to offset the fetch-shock combo. Also with the phyrexian mana and Thoughtseize I'm set to burn my face a lot. Makes me consider Death's Shadow.

Lol yea that's why I put him in mine too

Like you said, looks mean xD

DISCLAIMER: These suggestions are in context of Grixis Twin, however I think that UR Twin would be a far better choice than Grixis. Adding the black makes UR Twin clunky and makes its best two sideboard cards (Blood Moon and Ancient Grudge) either far worse or unplayable in the deck.

Mainboard just isn't the place for a Blood Moon. It's meant as a sideboard card to hose Bloom Titan, Jund/Junk (or 3 color decks in general), and Tron, and to deactivate mainlands vs. Affinity, etc. You don't want it mainboard because it isn't really your "plan", it's more of a tool.

Again, you really don't need to mainboard Surgical Extraction either. You'd use it in the sideboard to combat Twin, Bloom Titan, Storm... just combo in general. However, it isn't great in fair matchups.

Boomerang isn't good in a Twin deck. You'd much rather be Remanding to effectively get a Boomerang + a turn and an extra draw. This isn't to mention how pivotal Remanding your own spells against a blue opponent is.

Spreading Seas is only really worth it against Tron, otherwise you're tapping 2 mana to cripple the opponent's colors (rather than Stone Raining them). This means that Seas is a terrible draw when you're behind, and doesn't really stop your opponent from using the land anyways.

Serum Visions is almost necessary in a Twin deck so you can dig for answers and combo pieces. There really is no better cantrip to play, and it always feels good to resolve a Serum.

You could include either Vendilion Clique or Tasigur, the Golden Fang as additional threats and utility. Clique is especially good against blue opponents (to cycle away extra Splinter Twins), Tasigur helps stave off aggro, give you a clock, and block Goyfs, Rhinos, etc.

At least one Cryptic Command would be good, that card is bonkers. With Snapcasters, you really want the fourth.

Rakdos Charm is not a good sideboard card because decent Twin opponents play around it. Sowing Salt is slow and unnecessary, since Tron is already such a good matchup (between Twiddle effects, Blood Moon, and counterspells). The third Anger of the Gods isn't necessary unless Collected Melira/Elves is a huge thing in your area.

Finally, I'm not convinced on maining the Thoughtseize effects. It is fine when you have them in your opener, but you can't afford to draw them in the late game. It's too risky IMO. Some Seizes in the board is fine against blue opponents, tho.

Sorry for the word wall.

Oh, and running more than one basic mountain in a Blood Moon deck is suicide. Also, Scalding Tarn > Bloodstained Mire since you need to fetch blue mana in the case of Blood Moon.

Where are your Serum Visions and Gitaxian Probes? Also, I'm pretty sure Anticipate is better than Telling Time.

I swapped Anticipate in, but I have no desire to make room for the cantrips.

Surgical Extraction in the main seems a bit sketchy. I really think the cantrips, like awesomename suggested, are very important for your deck. I'd seriously consider them. They're better than Anticipate, too. Costing 1 is big.

I took the Extractions out of the main because as much as they can be a silver bullet at times, they're often not the card I want to draw. For now I'm going to add some more counter magic to the main because I want to be able to deal with whatever they're doing on turn 2/3. I feel like the optimal line of play is;

turn 1: hand disruption

Turn 2: counter magic/anticipate/more hand disruption+bolt mana up

Turn 3: counter magic/electrolyze/kolaghans command/exarch/mite

Turn 4: win. Or continue to keep them off what they're doing and disrupting their line of play until it's safe.

I do think my spot removal could be better, but with a decent amount of hand disruption I only have to worry about either creatures of non-creatures. I switched Spell Pierce for Izzet Charm and I've got a Slaughter Pact coming in the mail. It's something I'm thinking more on.

Based on your title I assume that you know that Splinter Twin has been banned from the Modern format.

Yeah I was in the middle of switching it and my internet exploded. What are your thoughts on the build?

I think since you aren't a tempo until twin deck anymore, Remand becomes a lot worse, especially with tron and affinity in the meta. I think another cryptic and maybe Blightning is a good add.

Or perhaps you can main a sweeper like Kozilek's Return

I like the idea of Kozilek's Return but in this deck it just wouldn't be as good as it should be. What do you think about Tasigur's Cruelty in that spot? Upside vs Blightning is it could probably cost 1. Downside is it could cost more and it doesn't burn for three, which is nice. K-Command or more Electrolyze may be relevant. I also really like Arc Trail but that might just be a pet card.

Tasigur's Cruelty might be overloading on delve spells. Pyroclasm is pretty good as a sweeper, especially since you will be seeing a lot of linear decks ,though it can't interact with manlands like kozileks return.Electrolyze is definitely really good, and the main problem with Arc Trail is that it doesn't cantrip, even though it is less mana and hits a bit harder. Also its a dead card if the opponent doesn't have any creatures. I don't believe you can target the same thing twice with it. You can try it out. It's probably meta dependent.

Hey, Crumble to Dust is the exact same card as Sowing Salt, but easier to cast and cheaper to purchase. Just sayin'.

Engineered Explosives <-- over Anger of the Gods easier to cast in a three color deck, you're not committed to on turn 3.Ratchet Bomb <--Same as above Dreadbore <-- for Planeswalkers in the Side.Ancestral Vision <-- Do not underestimate drawing cards, controls wetdream <-- synergy with Yahenni's Expertisemore Tasigur, the Golden Fang maybe x3drop Young Pyromancer he's better in a dedicated strategy and worse without Gitaxian Probedrop Faithless Looting better if you were running cards with Madnessconsider Spell Snare, Spell Pierce, Familiar's Ruse <-- +1 for synergy with Snapcaster Mage.More artifact hate and explore other options for Graveyard hate.Up the count on Thought Scour to fuel Delve.Tip, prioritize creature's for discard spells, and you can focus more counterspells on noncreatures. Drop Remand

Nice deck. Tasigur really shines here

Thanks. Delve is really powerful. Too bad so few of the cards are playable at higher levels.