Historically, in Magic, two drop creatures are usually the most efficient. There’s a reason people play maindecked Spell Snares in Modern. Some examples: Snapcaster Mage, Tarmogoyf, Spirit of the Labyrinth, Meddling Mage, Putrid Leech, Scavenging Ooze, Pack Rat, Dark Confidant, Baleful Strix, Thalia, Guardian of Thraben, Arcbound Ravager, Quirion Dryad, Lord of Atlantis and its ilk, Young Pyromancer, Precinct Captain and so forth. This is only what I can come up with from the top of my head. Sure, there are creatures with other casting costs, which are definitely good, but two just seems to be the sweet spot.
What can we do with this information? Well, the title of this post says pretty much: if all our creatures are of the same casting cost, we can bring them all back with Immortal Servitude and since we don’t want to go too high on the curve, two is a good spot to put all our creatures in. So, now the question is, what do we use here. Since I tend to go with monocolored decks, we can choose either white or black as our color. So, the first step is figuring out all the creatures we can use use in standard:
(Note: I did put some thought into using one-drops, but that didn’t feel good, as the number of decent one-drops is much lower then the number of decent two-drops, although using four mana for the Servitude would be much, much better than using five.)
So, now our first job is to prune these lists. We do have room though, at 23 and 21, we can drop most of the creatures. We only need about 30 or so creatures for the deck, so at most eight different cards, unless we want to get fancy against Bile Blight, which is now premium removal. Probably not.
On the white side, first, we’re not interested in being defensive, so we can take out the wall and the Concordia Pegasus. Second, I don’t think we’re going to be using anything to trigger heroic, so we can take out all the heroes and the Fencing Ace as well. Lets also not play the vanilla creatures. I don’t think we’ll have mana to put into the inspired, so we’ll drop God-Favored General. Keening Apparition works, but is probably better in the sideboard. Vanguard of Brimaz could be good, but if we put Mutavaults into the deck, and don’t have any heroic enablers, Sentinel Sliver is actually probably better, but I don’t see why we’d use him either. Capashen Knight requires mana we don’t want to be using and we’re not that interested in lifegain, so lets lose Boros Mastiff and Oreskos Sun Guide.
For the black, we can again lose the vanillas and the 2/2’s with a downside. Again, not really interested in life gain, so dropping the lifelinkers, and not interested in being defensive, so taking out defenders and 1/3 guys. Tavern Swindler’s ability might be tempting, but its unusable. Couple of the bestow guys are just too expensive to bestow, so I’ll take them out as well as the only remaining flier, alhtough that could actually be good. We need to lose something though. Corpse Hauler is also a victim of this philosophy.
This leaves us with:
In both cases, the creature quality is not quite as high as one would hope, but with a couple of exceptions, these are all cards I might use in standard anyhow. Actually, there’s two exceptions in each list, so this might very well be fixed in Journey into Nyx, and this deck might become much better. There’s even a chance Cavalry Pegasus could be good, as many of the other cards in white are humans.
So, in order to enslave our dead, we need five mana. To get to five mana in a reasonable time, we probably need at least 23 lands. Since we want to hit the Servitude, we need to plenty of those in the deck. This doesn’t leave us with much room for other utility cards, but we can use some. Perhaps Spear of Heliod or a planeswalker for white and creature removal for black.
Sideboarding would be hard, because we don’t want to lose the innate synergy of this deck and the power of servitudes. On the other hand, we’ll have some pretty poor creatures in the deck, so taking them out is going to be quite easy.
In the end, this isn’t a very competitive deck. Just a pretty straight-forward aggro, which might win out of the blue every once in a while, but probably not that often. On the other hand, some of the cards could bring all sorts of strange benefits with their abilities. Hating on your enemy is always nice, as well as drawing cards.