Chandra, Torch of Defiance she can immediately pay back half the mana used to cast her or even better she can be impulse draw that does something regardless of if the card is cast or not. Her last two abilities work as pretty nice removal for medium to small creatures. So very many things will die to 4 damage. Can't count on getting to the emblem but if it happens that's a free spell with every spell cast.
Court of Ambition and Court of Ire if their only effect was to grant the Monarchy then I'd call them overcosted but along with card draw they'll dole out life loss or damage. One even causes discard if my opponent's are silly. With my commander's goad ability holding the monarch should be simple. Even if it gets passed around though, that just means there is additional incentive to attack that person.
Daretti, Scrap Savant a number of strong support cards in this deck take the form of artifacts. Artifacts that are likely to be destroyed like Conjurer's Closet and The Chain Veil. Daretti will help those things stick around.
Karn, Scion of Urza the +1 of this walker effectively reads draw 2 cards. This is pretty amazing card draw.
Liliana Vess it's midly annoying that the tutor is to the top of library but the ability to control your draws to this degree is pretty incredible. That she also hurts my opponent's advantage and has some slim chance to reanimate everything is again pretty cool.
Liliana, Dreadhorde General she creates tokens to protect herself and has strong removal abilities on top of a crazy draw ability. It doesn't even matter why my creatures die, she still is just like "DRAW CARDS, STUPID!" lol.
Ob Nixilis Reignited at a base this is just draw a card every turn. Added bonus of destroying some real threats and maybe possibly perhaps dropping an emblem to harass that Niv-Mizzet, the Firemind player.
Professor Onyx Not just card draw but card selection out of the top three. Interacts with her Liliana kin by filling the graveyard and kills everyone's largest power. Not always the best thing to kill but better than being allowed to select a useless token to sac.
Tevesh Szat, Doom of Fools +1 to draw 2 cards consistently and might even work as a good sac outlet for Kardur allowing me to draw 3 and then reanimate or recast him to repeat the ETB. Overall just works really nicely here.
Ugin, the Ineffable A bit of mana reduction for some of the deck's best support effects and consistent draw. Running both Ugins is never bad.
Yawgmoth, Thran Physician proliferates, draws, sacrifices, even acts as removal. What's not to like?
