First of all, Shadows over Innistrad Draft is a two color format. Period. You are not going to splash for a third color to make some janky thing awesome, you are not going to spurge out with color fixing to get some three color shenanigans on. There aren't even any three color cards or bonuses to be had. You figure out what two colors you're in, and you start drafting towards your archetype. And the faster you figure that shit out, the less dead cards you'll have at the end.
Secondly, the synergy in this set is very high. Like, probably more than Zendikar high. It is not enough to simply draft "good stuff" in your colors, you want to draft shit that works with the thing your colors are trying to do. In fact, synergy is so extreme in this set that some player is probably going to draft a Ravenous Bloodseeker third-pick and be right to do so.
This is a legitimately bad card. Except that the Black/Red Vampires archetype and the Blue/Red Prowess archetype would actually pay 2 mana for a creature that simply let them discard a card every turn at instant speed. We'll get to that in a bit.
Now, let's talk about the special mechanics of the set:
Delirium
I don't understand the flavor here. I treat people with delirium all the damn time, and it's nothing like this. Delirium in the real world is a temporary increase in confusion. So you'd think the game mechanics would be some sort of thing that would come and go making things "go crazy" for a while. What it actually is in the game, is a power-up status that you get at some point into the game and then keep forever. So that's a flavor fail. Mechanically you either "have delirium" or you don't, and you have it if four or more different types of cards are in your graveyard. The types are Creatures, Artifacts, Enchantments, Sorceries, Instants, and Lands, which means that you need to get 4 out of 6 of the types into your graveyard to get the powerups. Instants and Sorceries play themselves into the graveyard, Creatures die easily, and getting the other types into your graveyard requires planning.
The benefits of Delirium are completely fucking random. Most spells don't give a rat's ass whether you have Delirium, and the ones that do get benefits that range from "who cares?" to "holy shit!?" It is entirely possible to draft a deck that doesn't care whether it has Delirium, and it is equally possible to draft a deck that wants Delirium and isn't going to get it. Making a deck that cares about getting Delirium and also gets it when it matters takes a bit of doing.
Getting Delirium for the Hound of the Farbogs might let your five mana creature trade its life for two 2-drops. Might not. No one cares, and you probably aren't going to play this fucker even if you think you're going to get Delirium most games.
Getting Delirium for the Soul Swallower puts your opponent on an incredibly short clock. This makes both the Swallower and the Delirium incredibly high priority if you open a pack with one.
Madness!
Blue, Red, and Black have a mechanic called Madness. Cards which have Madness have an alternate cost where you can play them if and when they get discarded. Madness therefore requires two things to function: firstly a card that has a Madness cost, and secondly an effect that makes you discard a card so that the madness cost can be paid.
Some Madness cards have madness costs that are lower than their normal costs, and the more of them you have the more discard outlets are prized. In effect, being told to discard a card is ramp if you have a card in your hand with a madness discount. Many Madness cards are card types that normally can't be played during combat or your opponent's turn (Creatures, Sorceries, or Enchantments), which means that if you have instant speed discard outlets, you can give those cards Flash. Still other Madness cards don't do any of that shit, and some Madness cards even cost more mana to Madness than they do to cast normally - but remember that discarding is often a "cost" of something, and "paying" that cost by playing a Madness card is just like getting the benefit for free. So for example, if you have an effect that lets you rummage or loot ("paying for" a card draw with a discard), having a Madness card in your hand to play turns that effect into straight card advantage.
This means that Madness is a critical mass type thing. If you can get enough Madness cards and enough self-Discard effects, you're going to see some big turns. But if you only get one or the other, or not enough of either to see both at the same time, it's all so much blank text. But it also means that if you're in Black/Red Vampires, Black/Blue Zombies, or Blue/Red Prowess, you should seriously consider cards that discard cards out of your hand even if they do so at a shitty exchange rate.
Broken Concentration is already an Instant and even costs more mana to Madness out. You only use the Madness if you're getting something for discarding. You're paying an extra mana to cast it as a discard instead of as a regular card. On the other end of the spectrum, the Twins become significantly cheaper when discarded, so if you had the option to pay mana for the fucking privilege of discarding you would do it. In the middle are cards like the Masquerade, which gain only that they can be cast when they wouldn't normally be able to be cast through the magic of discarding.
The Ravenous Bloodseeker gives you almost nothing for discarding, but it allows you to discard whenever you want. That means that if you have a card like Stensia Masquerade, your Ravenous Bloodseeker can flip call for a discard after blockers are declared and make that enchantment into a combat trick. Or it would let you flash the Twins into play at a deep discount. So if you have cards like the Masquerade and the Twins, the Ravenous Bloodseeker becomes really good as a casting aid. But it basically doesn't do shit for your Broken Concentration.
The Scholar and the Prophet give you a fucking card from the top of your deck when you discard, so using them with Broken Concentration is fucking card advantage. That is haxx!
Green and Red have Werewolves. These showed up in the last Innistrad, but now they are awesome instead of being a bunch of coasters and the Huntmaster. Each Werewolf comes into play as a human werewolf, and if a turn goes by without either player casting any spells, they flip over into non-human werewolves during the next upkeep. Once on the werewolf side, they flip back into humans during the next upkeep if a player plays two spells in a turn.
The important thing here is that while most werewolves in the old set were under-curve as humans and over curve as monsters, in this set almost all of the Werewolves are on curve as humans, and then over-curve as monsters. That makes almost all of them playable even if you don't have any of the werewolf tribal bullshit.
The bottom line is that in limited you would be willing, but not excited, to play a creature that was just the human face of those cards. They are basically on-curve. And then when they hulk out, they are notably above curve. This makes them threats on the board state later in the game even though you can play them in the first few turns. This is a huge departure from the old Werewolves who where mostly kind of shitty if you couldn't figure out how to get them to transform.
Skulk is the new combat power that mostly lives in Black and Blue. It's a form of Evasion where a creature cannot be blocked by creatures that have higher power than they have. Skulk + pumping is thus pretty fucking awesome and basically unbeatable without double blocking or combat tricks on the other side.
A head's up: Skulk is much better on creatures who have a Toughness higher than their power than it is on creatures that go the other way.
Color Identity
There are lots of cards that have a face that doesn't cost any mana. You bring a card out one way and it flips over and the reverse side doesn't have a mana cost, but it still has a color. These things have a little colored dot that tells you what color they are supposed to be. Which is the same color as the giant colored border, and people are absolutely not confused as to what color these flippy cards are. The important thing is that there a number of cards that produce things from another color that people think are supposed to go into that color combination - but there's no reason to do it that way. You are still making decks based on what kinds of mana things cost, not on what color identity shit has - this ain't Commander.
The Town Gossip Monger is thematically a Red/White card, but it doesn't have to go into a Red/White deck. It kind of benefits more from being in Black/White actually.
Rise From The Tides is a Blue card that makes Black Zombies, but its best home is in Blue/Red Prowess rather than Black/Blue Zombies. Indeed, this card is basically garbage in a deck that tries to push the Black/Blue Zombie creatures.
Both these Black Zombie tribal cards care about Zombie Creature Cards, while Rise From The Tides is not in fact a creature card and wants your deck to have as many cards in it that are not creature cards as possible.
Many cards in White, Green, and Blue have the tag "Investigate." That puts a non-creature artifact token into play called a clue. It does absolutely nothing but you can spend 2 mana to sacrifice a clue and draw a card. At its most basic level, every card with Investigate is basically a cantrip that has an additional cost that you can choose to pay later.
There are also cards, mostly in Green, that do a thing whenever you sacrifice a clue. Note that they do not require you to sacrifice them for their own 2 mana card draw ability, so you can sacrifice them to other stuff and still get those rider effects if that's what you're doing.
Investigate is super interesting in constructed because there are decks like Modern Affinity and Standard Thopters that are quite happy to have a giant pile of artifacts lying about, and the prospect of casting spells that simply leave extra useless artifacts in play is quite interesting. In this format, there are only a couple of cards that give you any real benefit for leaving clues in piles, mostly it's just buying cantrips on layaway. But any deck with Green might have cards in its list that would prefer you to crack open clues later rather than earlier.
Mostly Green gets cards that reward you for having Clues or waiting to sacrifice them until your combo pieces are in play.
Most cards with Investigate are simply expensive cantrips that you can choose to buy over multiple turns. Which means that a lot of them are really good even when you don't have anything that cares about what you do with your clues.
OK, let's start the Archetypes.
Allied Colors: Tribal
The allied colors on the wheel have creatures that share designators and spells that care about creatures with those designators. To a first approximation, drafting all the cards that mention your color combination's tribal affiliation and then making a deck is a pretty good strategy. You can squeeze a bit more synergy out of it by figuring out what your tribe can do and then working around it, and you should. But you can probably go 2-2 even without.
Black/Red Vampires
Black/Red is heavy on the Vampire Tribal and heavy on the Madness. Once you know that you're bringing the Wrath of Falkenrath, you should draft every Madness card you see in Red or Black and every Vampire that comes around, even the shitty ones. Also, you should invest in some discard outlets. Fortunately, a lot of cards in the set are two of those things at the same time.
This deck is aggressive as fuck. The goal is to play cheap high power creatures on curve and bludgeon your opponent to death before they get to do whatever the fuck it is that they are trying to do.
Think differently about discard effects. The Insolent Neonate is a ramp card. You play him on turn 1, attack with him, then you sacrifice him and play the Blood Mad Vampire for only 2 mana, and draw a card to replace the lost Vampire. The card text says you are Two-For-Oneing yourself for no reason, but if your Madness Triggers are firing correctly, this is actually a card-neutral way to get bigger vampires out for cheap.
Then you play the Masquerade or a burn spell to force your Bloodmad Vampire through on turn 3 and you have a 5/2 against an empty board. It's a very fast clock.
Werewolves are mostly aggressively costed as humans. So you can pretty much just make a creature deck with a bunch of on-curve thugs and smack your opponent around with them. And if you ever run out of gas, all your werewolves flip and then you can try to push through the enemy line with bigger, badder monsters.
There are a few Werewolf tribal shenanigans, and you'll want them. But mostly you just want all the Werewolves you can get. There are also a lot of Wolves, and Werewolf tribal boosters usually trigger off regular wolves as well. So you aren't quite committed to drafting only flippy cards and showing every other player what you're up to. But um... you really are showing everyone what you're doing. You're gonna draft every Werewolf that comes your way, and everyone will know who's drafting Werewolves. It's a strong archetype, so I can easily see it being overdrafted, but you'll know right away and be able to jump off into something else.
The Red/Green Werewolf Tribal stuff is pretty strong and strongly encourages you to simply draft a big pile of Wolves and Werewolves.
Green and White have a bunch of creature cards that are humans and a bunch of ways to trigger off of humans coming into play and/or dying. Your basic concept is that you play bears (Creatures that are about 2/2 for 2 mana) with upside and also have a few things that collect +1/+1 tokens. Conceptually, you throw down dome soldiers and shit and charge into combat, and if that isn't enough to take down your opponent you overwhelm everything with an Unruly Mob.
Literally an Unruly Mob. When you're drafting Green/White Humans, grab as many of these fuckers as come by.
You can get a lot of value from having your creatures die. Which is good, because it may take two of your creatures to take down some of the nastier vampires and demons.
Blue/White Spirits
I honestly think this deck has too many moving parts. There are spirits that let you flash your spirits and spirits that let you bounce your spirits and spirits that give you clues for playing spirits and spirits that tap your opponents' shit when they come into play,and if you actually got all that shit you'd have a value engine that also tapped down your opponent's stuff. But you aren't getting all those pieces in your deck, let alone actually rolling all that shit into play. The combo pieces don't do enough if you only have a couple and you end up having to run some mediocre off-archetype creatures because it's Draft and what the fuck did you think was going to happen?
Practically speaking, what White/Blue spirits is all about is the fact that there is very little in the way of flight in this set, and White/Blue Spirits has most of it. With some tap-down and removal you can limit what your opponent can throw at you on the ground while you peck them to death with tiny bullshit in the air. It's a thing.
Yeah yeah, combo pieces. Whatever. The important part is that your opponent probably can't block these fuckers, so if you can stay alive you already have your win condition sorted.
This is a weird deck, because most of the pieces that seem like they'd fit in it actually don't. A bunch of the cards care a lot about Instants and Sorceries, while a lot of the cards care about Zombie Creature Cards, and there are Instants and Sorceries that make Zombies but aren't actually Zombie Creature Cards at any point that the supposed combo pieces try to check for these things. Sigh.
Some of the blue zombies do exciting shit involving Discarding to do recursion. And that actually encourages you to get yourself a Vamprie subsuit. Some of the Black zombies care about Zombie creature cards, which encourages you to pass on the Madness spells for more pokemon. It's all very confused, and you can easily end up drafting a deck with a lot of Nombos.
Both these cards are bombs that check for zombie-related card types in your graveyard. But notice how they aren't checking for the same card type.
These are both zombie themed cards, but one combos with the Colossus and the other combos with the Rise From the Tides. And they both do fucking nothing for the other one.
Ah well. At least the Corpse Trawler combos with a spell token strategy and a creature card strategy.
Where the allied color archetypes mostly revolve around grabbing a tribe and running with it, the cross colored archetypes... don't. You still need to reach for synergy here, because otherwise a tightly drafted synergy deck is going to kick your face in. But here your synergy is going to be helpful mechanics rather than simple tribalism.
Blue/Red Prowess
Probably the most focused and coherent of the cross-color archetypes, Blue/Red Prowess is hard core but also easy to fuck up in drafting. You pick up creatures that benefit from you casting non-creature spells, and you pick up spells. Once you have Prowess on the table, those weird blue cards that durdle around filtering your deck become card neutral combat tricks and that's really good. However you still need to draft enough creatures that you aren't left with a pile of bullshit that can't field an actual army.
There are Prowess Creatures at common, but you have to remember to actually do it.
Red/White Aggro
Many cross-color combinations have a special cross-color enchantment that you will be able to draft if you are in those colors because fucking no one else wants them. For Red/White, you have Nahiri's Machinations.
Play aggressive. Trade up where you can, force your opponent to make bad blocks to stay alive.
You probably are only going to draft Green/Black if you open the Hypno Toad.
All hail the Gitrog!
Play with like half your deck in the grave.
Profit!
Black/White Good Stuff
There isn't a lot of synergy to be had in Black and White. There are cards and Tokens that are White and Black, but you don't care. Both the Westvale Cult Leader and the Wayward Disciple are more at home in a White/Green deck. The Black/White Enchantment gives all your creatures Skulk and gives you a mass pump, which is nuts because it makes it basically impossible foryour opponent to kill your stuff by blocking it one for one. Prioritize creatures with toughness higher than their Power, but even creatures with even stats can be amazing.
You're not drafting White/Black because you got passed Behind the Scenes, you're drafting it because you opened Sorin or got passed a White Bomb just after opening a Black bomb or vice versa.
Defensive creatures will keep you alive until your bombs come out, and with Behind the Scenes in play you can force your opponent to take damage or accept bad trades.
I'm not really sure why you'd end up being in Blue/Green Clues. Altered Ego is nice, and it can win you some games, but it's not exactly the kind of bomb rare that would make you say "Gosh, I guess I'm playing Blue/Green Clues now." Probably you drafted some decent Blue or Green spells and then you got passed a pack where the best card was Ongoing Investigation.
Weirder things have happened.
Many of the Blue/Green Clues creatures are good at keeping you alive. Draft them.