Of course everyone knows how scary it is to have an archenemy like Drana, Kalastria Bloodchief, Gideon Jura, or even All Is Dust, but sometimes it is the henchmen, those last few cards that make your main deck and the first few cards in your sideboard that really make the difference.
Cards number twenty-one and twenty-four are not typically as important as your biggest bombs, your most versatile removal, or your most synergistic threats, but that doesn't mean that you should give them any less thought or respect.
Pay close attention to how you pick your henchmen. They can make all the difference between winning and losing.
#21 Versus #24
Whether you draft that Demystify that you are going to sideboard in a few key situations, or that Lone Missionary who would act as one of the final cards in your main deck depends on a lot of different factors.
If it is late in the draft, and you can tell that your curve is lacking, and that you would legitimately want to include a Lone Missionary in your main deck, then you should take it over the commonly sideboarded (and occasionally main decked) Demystify. Heck, if you need something for your curve, then even a Glory Seeker would be a better choice for you than Demystify, as that will allow you to satisfy your deck's needs, rather than its wants.
But if you already have another decent two-drop that you could run, and that Lone Missionary would merely provide you with an upgrade over your lackluster Glory Seeker, then that should tip the scales in favor of the potentially game breaking Demystify.
That is, unless your deck really needs help in the early game. Either because you need yet another marginal two-drop to help you fill out your curve, or you really need the 4 life from Lone Missionary to help you survive your opponents' early onslaught while you get ready to take over. In these cases, you should again take the life-gaining two-drop over the umbra destroying Demystify.
But whenever you think that you would probably leave that Lone Missionary, or that Glory Seeker, or even that Ikiral Outrider or Affa Hound in your sideboard, then you should go with the potentially very relevant Demystify.
Similarly, if that Lone Missionary that you are looking at would provide only a slight upgrade for you over something that you already have in your deck, like a Glory Seeker, then you would probably be better off with the sideboardable Demystify.
#21 Versus #24, the Prequel
When you are deep into the third pack you can carefully examine what you have already drafted in order to figure out what card will provide you the most equity given exactly what you have, while expecting little to no subsequent improvements.
But earlier in the draft, say late in the first or even second packs, you won't know exactly what you are going to get, and consequently what you are going to need.
At these points, there is significant value to playing things a bit safer to help offset the risk of something going awry later.
If it is deep in pack two, and you already have an excellent early game and you are well on your way to getting to 22-23 playable cards, then you should definitely take the Demystify over the Lone Missionary.
But, if it is late in pack two and you notice that there are some holes in your curve that you are going to need to fill, then you should probably go with the creature.
These holes don't need to be in your early game to incentivize you to take the two-drop. Heck, you could already have a pretty good early game that might only need a couple more cheap creatures from the final pack to be where you want it to be.
The thing is: if you need to fill in holes going into the third pack, you want to give yourself as much freedom as possible to do that. You don't want to get into the situation where your first few picks from the third pack don't exactly satisfy your decks needs, and you're stuck scrambling to fill the problem that you foresaw late in the third pack and an early drop problem because you figured that it would sort itself out because you were on schedule to have a good early game.
If you are deep in pack one, I would recommend even more strongly for you to take the Lone Missionary over the Demystify because having that solid, if a bit underwhelming two-drop, in your pool will give you that much more freedom as the draft progresses. If you have that Lone Missionary in your two slot, you probably won't feel like you have to take that Caravan Escort over that Mammoth Umbra, or that Ikiral Outrider over that Ogre's Cleaver.
Remember, just as you will get plenty of shots at two-drops later on in the draft, you will have plenty of looks with which to see more Demystifies. It is perfectly okay to miss a shot at an often irrelevant sideboard card like a Demystify in favor of the security that having an extra two-drop offers.
Figuring Out How You Are Going to Round Things Out
How do you decide if you should be playing your cheap, but relatively ineffective (in Rise of the Eldrazi Limited) Glory Seeker or if you should be playing your powerful, but difficult to cast It That Betrays or Pathrazer of Ulamog.
Like when you are deciding between drafting that Lone Missionary, and that Glory Seeker, you have to decide if you want to go for the card that has a big chance to make a small difference, or the card that has a small chance to make a big difference.
The first thing that you need to ask yourself is what are your decks strengths and weaknesses. If your deck has a very strong late game, but it needs some help getting into there, then you obviously run the unassuming two-drop.
If your deck looks like it will have an easy time stalling things out and advancing to the late game, but very few ways to win, then you should go with your monstrous Eldrazi threat.
If your deck already has a rock solid early game, and you don't see how an extra 2/2 for two would do much for you, then you should again go for the big Eldrazi.
But what if your deck is lacking in both its early game and its late game?
Then you have a tough choice to make.
If you are drafting, then the pick could really go either way depending on where you are in the draft.
If it's midway through the second pack, and you are choosing between the potentially devastating Spawnsire of Ulamog and a Glory Seeker, then I would typically go for the Spawnsire of Ulamog because it will probably be easier for me to fill out my early game a bit later on than it will be for me to find a card that I can ride to victory in games that go long.
But if the pick is instead between a Glory Seeker and the extremely difficult to cast Pathrazer of Ulamog, then I will likely lean towards the Glory Seeker unless I feel like I am in desperate need of a way to close out the game.
If it is deck building time and you already have both of the cards in your pool, and you are figuring out how to construct your deck, your question does not become any less interesting, but it becomes somewhat simpler.
Of course it will usually feel weird to have to choose between playing a two-drop, or an eleven-drop, but sometimes your deck doesn't give you any other options.
If you think that you will have a good enough early game to make yourself competitive except for maybe the fastest decks, but not really good enough to overwhelm a slower opponent, then you should probably go with the gamebreaker for your main deck.
If you are concerned with your early game, then I would definitely recommend that you lean towards the two-drop. But if you legitimately feel like you cannot win a long game, then you will often have to overlook some consistency issues in order to give yourself a real way to win.
Whichever one you go with, please keep in mind that you can easily swap them out for one another after Game 1.
Deceptively Similar Costs, Extremely Different Functions
Usually during deck building, instead of looking at a two-drop next to an eleven-drop, you will be looking at two, sometimes deceptively, similarly costed cards that provide very different functions.
While the choice between Glory Seeker and Pathrazer of Ulamog is a choice between two potential final cards, the choice between the solid Dread Drone and the often game breaking Ogre's Cleavers also tends to be one between two final cards.
A Dread Drone and an Ogre's Cleaver both tend to come online during the late stages of the middle or early stages of the late game. But while Dread Drone provides you with an immediate board presence, and helps accelerate you towards your biggest threats, Ogre's Cleaver requires a repeated mana investment to turn even your lowliest critters (even Eldrazi Spawn tokens) into deadly threats.
While Dread Drone is a great card to cast as soon as you get to five mana, the repeated mana investment that Ogre's Cleaver demands means that it's actually one of the last cards that you will want to make in your sequence of plays.
Like when you are deciding between Glory Seeker and a late game Eldrazi threat, if your deck has a good early-mid game, but is lacking in late game options, then you will want to go with Ogre's Cleaver.
While I would usually pick up the Ogre's Cleaver during earlier stages of a draft because it is abstractly more powerful, it doesn't require any sort of color commitment, and because it serves a more unique role than Dread Drone. If you already have an Ulamog's Crusher and a Pestilence Demon in your deck, then it will be very difficult for you to pass up a Dread Drone.
When you are drafting, always be careful to keep in mind exactly what you've drafted, what you still need to fill out your deck and what you can reasonably expect to get during the time you have remaining. If you are on track to get everything you need, then you can pick up things that you want that have more potential upside.
When you are building your deck, you will need to decide between the card that will give you more consistency and the card that will give your deck more raw power. If you feel like you are in a good position to win your fair share of normal games, then you will probably want to go with the card that offers you more consistency.
But if your deck has some serious problems closing out games, then you are almost always going to have to go with the abstractly more powerful card that will singlehandedly help you win more games.