The aim will be to put an early summoning out, then play cheap, small utility creatures until we draw phyrexian reclamation so we can start recycling. Bloodbond march is there so we can generate an actual advantage on each loop.
An example would be as follow:
*Have 2 summonings out, a reclamation and a march ( we have some decent amount of early card drawing to find those).
*Cast a small dude for B , he will immediately die and put his ETB trigger on stack, then trigger bloodbond march bringing the rest of the dudes in the grave.. the result will be multiple ETB triggers for just one black mana spent ( we can do this with fleshbag marauder to clear board, phyrexian rager to draw some cards, bloodhunter bat to gainlife/deal damage, Priest of gix to generate absurds amounts of mana, Pharikas mender to recover creatures or one of the enchantments, and phyrexian gargantua to draw even more cards at a higger cost of BB and some life).
*Buried alive is there to ensure we will have the creatures needed in the graveyard to bring back with the march, ex: if you have a bat in hand, search for the other 3 , so you can bring them back wen you cast the one you have, or search for gargantuas/ragers if you need to draw, etc.
*Once you are set up you can start a loop with the priest to generate mana ( but you will need to pay the life from the reclamation) as follows:
Cast priest for B, add BBB , priest will bring the other 3, adding a total of 12 black mana and alll of them will die immediately, pay 1B +2 life to bring one of them to hand, cast for B, he will bring the other 3.... repeat as necessary then return bloodhunterbat to hand instead so you can lop it and start gaining the life back and dealing some dmg,( remember 1BB+2life = 12 black mana, with the priest cycle, and 1BB+2life = 8life gain and 8 life loss for opponent with the bat cycle, so just switch accordingly)
Spend the early turns chumpblocking and trading when possible. Once you draw into bloodbond march or Phyrexian reclamation you can start getting advantage of creatures like Fleshbag Marauder and Rager/gargantua. Set up your reanimations with buried alive and recover missing pieces with Pharika´s mender.
Once we have at least one heartless summoning priest of gix will become a dark ritual of sorts so you can cast almost every black creature spell in your hand for free.
We wil achieve victory throug life loss via Bats and Grim guardians.