This is probably my favorite army to play, although I do believe Ob is competitively outclassed by Arlinn and Jace Beleren, and potentially even by Nahiri and Sorin. After playing a few games over the years with the demon and attempting to optimize this build, here's what I think:
The opening turn sequence is a great idea (sac zombie to draw a card). I'd take it one step further:
Use Ob to kill one of your zombies via an attack roll. So, on your very first turn, you summon 1 zombie next to Ob, and place the other 2 zombies at the max 5 spaces out (put them on a spot where Ob can be adjacent to both of them after Ob flies.) AT ANY PRICE the first zombie, then move Ob to be adjacent to the other two - attack one of them (likely rolling a 5v1 or 6v1, which is >91% chance to kill.)
This is where your first two turns can diverge; in the best universe you can pull an absolute banger of a second turn if you have Painful Truths in your hand, play that after killing the second zombie with Ob's attack. Now, all 3 zombies are dead and you've drawn 3 cards for it! Even better, on your next turn with Ob, you can roll for DARKNESS ARISES to potentially place the zombies back on the map within 4 spaces of Ob. In the alternate and crappier timeline, if you don't have Painful Truths by the time you choose Ob to be your active army card on your second turn, you can still use AT ANY PRICE to kill the last zombie and draw another card, and on the following turn you can roll DARKNESS ARISES. But, having Painful Truths first and getting that lucky DARKNESS roll will earn you SO MUCH momentum in most situations though, it's disgusting.
We need the following RNG luck to happen for that super successful second turn:
1. Ob kills the zombie with his attack, this is usually 91%+ chance to succeed.
(Gonna call this step 91% chance)
2. We draw Painful Truths before activating Ob on second turn. Assuming we go first, we start with 3 cards in hand, draw 1 for AT ANY PRICE, and draw 1 at the start of our second turn.
I could use a real math wiz for this one; if I have 12 unique cards with only 1 target "success" card, and I draw 5 cards, what's the probability I find that card? If I did the math right, I'm seeing 51%. I added (1/12)+(1/11)+(1/10)+(1/9)+(1/
. Also note that for this step we are ignoring blue's potential to Jace's Erasure our spell or use Geists/Pieces of the Puzzle to dump it to the bottom, which IS where Painful Truths is literally the worst card; having a draw 2 card as the last card in your deck is worthless.
(Gonna call this step 51% chance, I'll edit if needed)
3. We succeed the DARKNESS ARISES check, 12 or higher on the D20.
45% to succeed.
Final math: We need
91% success AND 51% success AND 45% success in a row. Maybe I remember something from my math classes 25 years ago where
if you want multiple event successes where each event has its own unique probability, you multiply their success percentages together, no? If that's right, then I see approximately 20.8% chance that all of these occur with successes, aka 20% chance each game that you get that ultra-powerful second turn. After all of my games playing with Ob, I would have pegged this at around 25% just on gut feeling alone, so my math at least
feels correct, if nothing else.
Onto my nitpicks with the army build itself:
As some others have mentioned, I think OP's Ob build will
struggle against the Ruiner (and/or any heroes-based white or blue.) In my humble opinion, black is naturally pretty good at fighting squad-heavy armies. Ob can make 1 squad creature disappear each turn, Killing Wave is disgusting if your opponent doesn't pay attention to their positioning (and it's even easier to use with a
flying Planeswalker), and you have 2 squads of your own. I'm not a huge fan of the Ghoul Vanguard for this reason - he helps to cement black's advantage against squads, but in a hero v hero fight he's just a bad hero, even more so when he can't use his SHAMBLING RANKS OF THE DEAD to move and attack with a Blighted Reaver, which is not present in this army.
I think the
Malakir Bloodchasers are WAY better at slaughtering heroes (and Planeswalkers, for that matter.) Although the Bloodchasers do keel over really easily due to 2L and 3T, the Ruiner by himself doesn't
really look forward to fighting them, since they can generally heal off any damage they take from his LASH OF TENTACLES when they attack him with their LIFELINK. It's probably gonna be a quick and bloody fight for both sides anyway. Plus, Rise of the Dark Realms gets much better value with these guys than the Restless Zombies or Eldrazi Scions, and I think the Malakir are a usable wincon and can quickly get good offensive momentum if the opponent sleeps on them; good to relieve Ob of a little pressure.
Spells, I think
Ever After is absolutely in the same boat as Ghoul Vanguard as a game object that horribly fails against heroes; playing it literally does nothing if your opponent has no squads. This card is pretty hard to replace with OP's spell deck given it is using many other good spells and it's already at the 200 pt limit. I think I'd replace it with
Corpse Lunge especially in tandem with putting the Bloodchasers in the army. This helps ensure that the Bloodchasers (or any squad you enchant with Duress + Dark Harvest) will annihilate their target - in most cases that target should be a hero or Planeswalker. We now have 10 spell points left, but I don't think any of the other spells are better than what's already here.
Thanks for sharing the post, this was enjoyable to read!