I have a question. What happens when I have both Leonin Arbiter and Aven Mindcensor on the battlefield?
Well, your opponent won't be able to search at all unless they pay {2} for Leonin Arbiter's ability. If they pay, then they'll only be able to search the top four cards of their library because of Aven Mindcensor. Sounds like a bad deal to me, though.
Draw step is a bit of a let down. Fatigue does skip it for one turn. There are other cards that care not about the Draw step itself, but any draw, reading basically "if you would draw a card, instead do not." Omen Machine is one example, though they get the benefit of a free spell or land drop each turn. Also of note, if you were about to win by removing a library and there's an Omen Machine, play will continue because they aren't drawing. Archmage Ascension similarly prevents game loss from an empty library, but only for one player. Recycle and Null Profusion are great options, but affect their caster, being given one, especially if your opponent is forcing you to discard, can be quite a lockdown. Maralen of the Mornsong is a great option, still allowing a Draw Step to happen, but replacing it akin to Archmage Ascension. Maralen also takes 3 life, and if you don't want your opponents to search their library for an answer right away, don't worry, there are options (Spoiler Alert: Mindlock Orb). Knowing this, the best option is likely Possessed Portal, in that it does make players skip all draws, and has a rather nice attrition mechanic, whittling away at any cards in their hand or on the field. (Spoiler Alert Second-Time-In-The-Same-Paragraph: a player may use Sundial of the Infinite to avoid the negative effects of the Portal on their own turn.)
-Main Phase
There's not a good way (at least that I found) to ensure that a Main Phase is missed except to skip an entire turn. Still, your opponent may give you the choice by putting out a Fatespinner. Just remember that if they somehow have multiple Fatespinners, nothing prevents you from choosing the same step multiple times... except Mindslaver abilities discussed previously (Illusion of Choice doesn't work because it specifically refers to voting). Side note, Fatespinner and Eon Hub is a nonbo, but Eon Hub is a great response to an opponent's Fatespinner.
Playing Land
So, you've made it to your Main Phase! (If you're saying "finally", just think of what a player newer than you, unfamiliar with any of the previous cards is thinking right now) Bad news, though: it's your turn and they cast Moonhold during your upkeep, before you have a chance to play a land or cast creature spells (not even an Ornithopter). Territorial Dispute also prevents players from playing lands, but requires its controller to sacrifice a land during their upkeep (which we've already discussed skipping), which actually goes well with some effects, such as Gitrog Toad. Limited Resources keeps people from playing lands if there are ten or more on the battlefield, which can be quite limiting in multiplayer (hope your opponents aren't playing land destruction). Worms Of The Earth is stronger than the previous options in that it does prevent lands from entering the battlefield, not just stopping players from playing them. The weakness of the Worms is that they have an ability built in to destroy them, but Eon Hub ensures it never triggers, and Indestructibility means someone could even pay the cost to destroy it, but it would still stick around.
Searching Your Library
Let's say you were able to play a land, but it's an Evolving Wilds. Aven Mindcensor puts a damper on its use; with Aven Mindcensor if there isn't a basic land in the top four cards of your library, you simply don't get one. Demonic Tutor? Still only able to see the top 4 cards. Leonin Arbiter basically asks for a bribe of two mana before anyone searches for anything, but that means if you're tapped out and your opponent does something that gives you the option to search, they're basically choosing for you. Mindlock Orb responds to any attempted search by simply saying, "No." It doesn't matter why you would search or what you would search for, the answer is always "No." Maze’s End is basically shut down by this, though you can still draw.
Casting Spells
Maybe your opponent is a little bit nicer. If it is your first turn, Orim's Chant or Silence can prevent you from casting any spells (except instants in response to them silencing you). Perhaps later, Render Silent can be used in response to your first spell of the turn to make sure you don't do anything from your hand. Or maybe you're playing a monocolored deck, so your opponent plays Iona, Shield of Emeria naming your color. You aren't out of the game quite yet, you can still play artifacts, right? Sure, technically right, but speaking of artifacts, they just played Painter's Servant naming that color, so now all spells are prevented except for theirs. This is (one example of) why Painter’s Servant is banned in Commander. (Brief aside, doing this and then equipping Iona with an Assault Suit means each player can only play spells on their own turn. Which would actually be kind of cool, until someone uses that opportunity to get rid of the Painter's Servant. If any followers pull this off, please submit the story to this blog.).
Grand Abolisher stops not only spell-casting (during its controller's turn) but also activated abilities of most permanents. Not planeswalkers, despite Teferi existing, so that's still an option. But otherwise he abolishes almost any "at the end of your turn" hijinks. Dragonlord Dromoka also helps protect its controller from interfering spells, but doesn't care about abilities.
Maybe your opponent is a bit more forgiving than completely shutting you out from the game. Instead of limiting you to no spells, you can play one per turn. They have plenty of options, Curse of Exhaustion is only on one player, but that's perfectly respectable in a duel. Eidolon of Rhetoric costs one less, but affects them as well, Rule of Law is the same but isn't a creature. Ethersworn Canonist has an ability is this same vein, but doesn't count artifacts toward the one spell limit, which is great for an opponent playing this in an artifact deck, but feels about the same as a Rule of Law to those unprepared across the table.
(Teeny-tiny tangent: because Mycosynth Lattice only changes permanents, not spells, Ethersworn Canonist and Mycosynth Lattice have no interaction, despite seeming like the Canonist would be undermined by the Lattice. Maybe on our next visit to Esper... or Mirrodin, I mean, New Phyrexia... or Kaladesh. Until then keep in mind Mycosynth Lattice with Inspiring Statuary is basically a super-Convoke).
So... Keep in mind, I originally wanted one turn to all be in one article, and we still have a lot to go through in just the main phase. But moving right along!
A fantastic reprint in Amonkhet, Aven Mindcensor is the ultimate punisher for tutors outside of Mindlock Orb or Shadow of Doubt. Restricting any search to the top four cards is brutal in a deck. Suddenly any demonic tutor is a crap shoot, giving them only a percentage chance to get what they were hoping for. On the downside, this hoses all mana ramp as well, leading to someone sitting on fetches, Kodama’s Reach or other cards because of the chance that it’ll just whiff on finding what you want. If your group is super competitive, perhaps Aven Mindcensor is one of the best hoser cards a white deck can have. Otherwise, it’s best to weigh the pros and cons of running something that ruins all tutoring for your opponents. It may deal with the Sharuum combo tutor deck, but it’ll also hose the RG Ramp deck as well.
