Life loss/drain
This deck aims to get Maralen out and keep her out using artifacts like Boots/Greaves/Darksteel Plate. Extra defense equipment will go to Ob Nixilis Unshackled to hold down a 13 life loss per turn synergy. Outside of the Ob Nix/Maralen play, the deck can also attempt to put together the Sanguine Bond/Exquisite Blood combo, or Isochron/Dark Ritual/Paradox Engine/Exsanguinate (edit: paradox engine banned! Gotta reevaluate) Mana doublers are peppered in to facilitate quicker combo construction. The high number of swamps helps ensure an ideal starting hand of 6+ land in order to maintain mana growth after Maralen hits the board. Nightmare Incursion and Sadistic Sacrament are in to help remove opponent's answers from their deck, reducing some of the benefit they get from tutoring every turn.
UPDATE:
I finally did it. Broke down and added Teferi's Puzzle Box for degenerate nastiness. For the uninitiated, TPB and Maralen work together like so: with both of them out on my field, both will trigger at the beginning of each player's draw step. The player controlling the triggers (me) decides which order they will go onto the stack if they trigger simultaneously. So, for my opponents, I opt to put TPB's trigger on first, then Maralen's. But on my turn, I put Maralen's on first, then TPB. The triggers then resolve in reverse order. For my opponents, that means they lose 3 life, tutor a card, THEN put their hand on the bottom of their library (and then are unable to draw that many cards, due to Maralen's static ability). For me, that means I put my hand on the bottom of my library, THEN lose 3 life and tutor. Essentially, only I will be able to have a hand, albeit a one-card hand. The only out for opponents is to tutor for an instant that they can play before TPB resolves on their turn. Thus, Sadistic Sacrament becomes an important card to remove any instant speed artifact/creature removal. Also, since my hand will eventually be reduced to one card per turn anyway, there is very little incentive not to mulligan multiple times, hopefully pulling Swiftfoot Boots or Lightning Greaves in my starting hand to get them out early for Maralen protection.
