Awesome - the whole deck is sort of one big combo. You need something that gives you mana for sacking creatures - like the altar or one of the treasure makers, something that draws a card when a creature you control dies, and Endrek. You'll probably need a Blood Artist effect as well, given how black is with every effect also costing one life. Then, once you cast a creature, you can sac the resulting thrulls and draw that many cards and make that much mana to cast another creature of equal or lesser value. You can often go on indefinitely, especially if you start with the high cmcs and work down. Shoot for a Gray Merchant of Asphodel to close out once you feel comfortable. That's the flashier win. Odds are, you can just plop down any Blood Artist effect and win off repeated sacrifice in the same combo. Endless Cockroaches and one of the mana makers goes infinite as well. That's the goal. In the mean time, you should have plenty of ways to keep hands and board states empty. There's a lot of support for a big mana sub-strategy, but it's mostly just backup incase my pseudo-storm wincon stumbles. There's nothing cooler than drawing out your whole deck and playing every creature. Big mana smooths out the ride incase the CMC rollercoaster doesn't go your way. Ideally, Endrek is the last thing you need, so that 5cmc doesn't feel like it's holding you up.
When new cards are printed, I'm generally only looking for more redundancy. I only just noticed that I missed, for example,Vindictive Vampire from RAV. Endrek Sahr, Master Breeder needs every copy of Blood Artist that exists so that it can survive every copy of Dark Prophecy that exists, for example.
Krav, the Unredeemed is definitely Endrek Sahr, Master Breeder's VIP. My deck largely consists of three broad spheres of need: card draw, mana production and life gain, in service of my overarching need for sac outlets.
Since Olivia's schtick makes every creature you cast a vampire, you might get more mileage out of Coat of Arms than most other tribal decks that have to compromise here and there.
Diaochan, Artful Beauty has probably inspired more time on the deck-builder sites than any other legend since Endrek Sahr, Master Breeder. You'll want to throw in the equipment that grants shroud, indestructible and protection from red, and the rest is up to you.
I always "complete" a deck within the artificial constraints I set for myself when I begin. I do a lot of homework before investing in a deck to make sure I can complete it. I make sure any deck I build doesn't want anything I can't afford. Sometimes, I add additional rules to my deck building, for example, Endrek Sahr has no tutors at all. Not a single card says "search your library". I also wanted every single card to be a permanent. So yeah, I put together very particular creations, but they never want for anything.
Commander has a very rabid anti infinite combo, MLD, stax, etc camp in its playerbase, and so long as those players don't support tactical scooping, I suppose all is well. I have no qualms about hardcore, anything goes players sticking to their mantra on this topic as well. It's the spirit of Commander at heart here. I had a guy tactically scoop against me in a threeway, and while I ended up winning, it was mind-blowing and caught me totally off guard. I decided that wasn't happening twice, and no deck since relied on an opponent to exist for any of its strategies. An ounce of prevention is worth a pound of cure.
I'm definitely in favor of giving the official rules more importance. Until today, the Commander vibe always seemed to be that house rules were the ideal state, and that the official rules were just suggestions for those unlucky enough to play against strangers. The new, "These are the rules, and you're not entitled to change them" vibe sits better with me.
I think threads like this are great arguments for building less interactive decks. Who wants a big Commander-like win by stealing all the creatures on the board and turning them back on their owners when they'll just invalidate you anyway. Build early turn combo decks so that tactical scoopers can only speed up your inevitability. I suppose I'm mostly just amazed that this topic even has two sides.
Typical concessions are perfectly fine. Tactical concessions of the trigger denying variety don't belong in any group that buys in to how Commander is currently marketed -- cutthroat groups only. If your deck hides behind the "Spirit of Commander" to stand a chance, you don't get to exploit rules loopholes to spite your table.
I almost suggested the rest of the fast mana suite, but realized that they require colors in the deck to be of use. I really struggle to think of anything I believe I would do better.
You'd have to work very hard and probably counterproductively to brew a list that doesn't resemble others on the net, because commander-oriented legends these days practically come with a deck-list included. I mean, I built my Endrek Sahr from scratch, but it shares about 25% in common with the average Endrek list according to EDHRec, where basics either don't count or don't benefit from multiples because otherwise I should be over 50%, I think. Now, it's a mono black list and it doesn't run any tutors, and it doesn't run Sol Ring and the like. Your mana base is 40% and probably homogenous across the color identity, and after that, just throwing in the obvious cards you picked your commander to play (and odds are, great minds think alike) and well, you'll be lucky to look half-way original if you're willing to sacrifice across the board staples like mana rocks and AAA answers.
I'll throw Endrek Sahr, Master Breeder into the mix. It's been a pet deck for years. Here's a link to the current iteration in the multiplayer forums, and underneath it, Salvation's deck maker.
https://www.mtgsalvation.com/forums/the-game/commander-edh/multiplayer-commander-decklists/805300-endrek-sahr-master-breeder-aristocrats-big-mana
https://www.mtgsalvation.com/decks/7992-second-chances