As you can see from the high version, the building process of this deck was very tormented.
At now I've obtained good but not excellent results (35W/27L), but I've made many mistakes during a lot of games so I presume that in better hands than mine this deck could perform better.



This deck has only one purpose: transfer life from your opponent to you, possibly maximizing the game events in parallel that can be triggered by the lifegain action (ie: +1/+1 counters on multiple Ajani's Pridemat, opponent that lose n x m life where n can be >1 thanks to Rhox Faithmender, Sanguine Bond, Suffer Past and so on).

Let's analyze the cards choosen :

Trained Caracal and Child of Night are mandatory choice, they are the main source for lifegain in this deck and they are cheap.

Wall of omens is a bit out of theme here but is great toughness works well with the star of this deck, hence Rotfeaster Maggot, and the "draw 1 card" ability is precious in a deck like this

Vizkopa Guildmage: it's unnecessary to explain its presence here, because it represents the essence of the deck. Maybe the question can be: why not 3 copies of it and only 2? After many many tests I can assert in a very empiric
way that 2 is the right number

Ajani's Pridemate: this creature can easily become a monster in a deck like this, especially when you be able to put 2/3 copies in play, so 3x is a mandatory choice

Necromancer's Assistant: Rotfeaster Maggot needs fuel (hence creatures from graveyard) and the assitant can perform this job very well. Therefore is great in combo with Gravedigger (that returns a creature from graveyard) and it's useful to create a "zombie" subtheme that can maximize the "draw card" ability of Graveborn Muse

Brimaz, King of Oreskos: absolutely out of theme, choosed only because is a very very strong card by itself, my mana curve suffers in the 3-mana slot and the feline token bonus can be useful for convoking Covenant of Blood

Rhox Faithmender Unfortunately only 2x, due to the rare restrinction. Fundamental card, can revert a bad match in a istant, combined with Sanguine bond or 2nd Vizkopa Guildmage's ability

Graveborn muse: is a bit out of theme here, but, following the Hakeem928's criterion, is a mandatory choice in every black (mono or not) deck. However draw some extra cards in this deck is precious because we need absolutely a Sanguine bond and to put in play as many 1/2 drops with lifegain as possible and its cost in terms of life lost is not a problem in a deck like this, full of lifegain possibilities

Gravedigger: it's not a first choice, but it's a zombie and it can be useful to return 1/2 drops died in the very first turns (ie: the omnipresent shock) or to grab in the right moment a creature that hits perfectly the mana curve, gone in the graveryard for the Necromancer's Assistant ability

Rotfeaster Maggot: this is the star of the deck; I know that is not too much appreciated in the players community, but in this deck is great because can combine its lifegain ability with Rhox Faithmender, Sanguine bond, Vizkopa Guildmage. I put 3x, because I want to play it in every game and -due to its great toughness- it is an ideal target when gone in the graveyard for an other Rotfeaster Maggot that enters in the battlefield. Extra bonus: it allows to exile dangerous creatures in the opponent's graveyard (excellent against black-based deck)

Sanguine bond: with this card in play, the chance to win is very high. Unluckily there are only 2 copies available, but the 2nd ability of Vizkopa Guildmage, that replicates its transfer ability, makes the deck consistent despite that.

Baneslayer Angel I hate this card, but it fits perfectly in this deck so I surrender and put in.

Battlegrace Angel that can act as a imitation of Baneslayer Angel to raise the deck consistency

Angelic Accord: I have some doubt about this card and about the right number of copies, but it very useful to exploit at maximum level the lifegain mechanism and to have some flying troops

Covenant of blood: the cost is very high but in this deck is frequent to have many creatures in play (average toughness high) so we can convoke it a lot of times. Its ability perfectly fits the deck's theme (transfer of 4 life) and its interaction with the key cards (Sanguine bond, c]Vizkopa Guildmage[/c], Rhox Faithmender) is amazing.

Suffer the past: 3x because is the best card in the deck and it allowed me spectacular victories, it can inflict 20 and more damage to the opponent in a incredible easy way when "echoed" by the key cards mentioned above but it is strong by itself and is great against spider-spawn/blue-recursive decks because it empties the opponent's graveryard.


Suffered exclusion: Death baron and Griselbrand. The first one is useful to trasform in menace sub-optimal card like Necromancer's Assistant or Gravedigger (deatouch and +1/+1 can make a huge difference) but its 2/2 is a pain and it has no synergy with the transfer life mechanism.
The second one is theorically perfect for this deck but games after games I reconsider its utility (very high cost) and switch it for a Battlegrace Angel.

A more defensive variant: -2 Angelic Accord / +2 Planar cleansing to revert bad match, to fill the opponent graveyard, preparing the battlefield for a winning Suffer the past

P.S.
I know that there are 61 cards, maybe I can remove 1xBattlegrace Angel but from a statistical point of view there isn't a substantial difference

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Probably I've found the right mix, with less zombies/more spells (+3xReprisal).
After those changes, I had a partial of 14W/2L so probably I'm on the right way.
it's the actual version:



Please report me any test done with the v5.7 that I suggest to try: now it's very balanced and funny. In the last turns, this deck can make an enormous amount of damage (combo Sanguine Bond+Vizdkopa Guildmage+Rhox Faithmender)