Garna taken as far into to combo as I can make possible.  Basic concept is to sac some stuff, mill, or otherwise get creatures to the yard.  Cast Garna.  With the ETB trigger on the stack, sac and "draw" a bunch of cards.  Ideally, have enough mana discounts and generation to make Garna free to cast so you can loop perpetually.  It could probably be tuned further, things like the gearhulk might not be ideal.

Absolutely BRUTAL deck to learn.  It is easily the most difficult to play deck I have ever built but also the one I am proudest of. 

Some MVP's:
-Soldevi Adnate generates some insane mana.  Garna gives it haste too!
-Skirge Familiar is unreasonably strong.  Discard a handful of creatures, cast Garna, get them all back, and repeat... seems fair...
-Pitiless Plunderer is probably my most tutored target.  One of the few ways to generate colored mana.  Also gets insane with Sifter of Skulls/Pawn of Ulamog
-Dimir House Guard is shockingly good here.  Provides a sac outlet that is hard to kill if you need that.  If not it can also (repeatedly) tutor for card draw (Lurching Rotbeast), mana (Pitiless Plunderer), a win con (Gonti/Aetherflux) or most other things the deck wants.

Notes:
Might be off by a card.  Sideboard is a wishlist.  Phyrexian Altar would be amazing.

Changes:
Oct 2020
Out:
Sequestered Stash
Reliquary Tower
Combustible Gearhulk
Wasteland Scorpion
Warstorm Surge
Ragemonger
Conspiracy
Bontu the Glorified

In:
Buried Ruin
1x Mountain
Liliana's Standard Bearer
Hollow One
Bone Miser
Drannith Stinger
Street Wraith
Viscera Seer

Changes Mar/21
Out: Final Parting
Aetherflux Reservoir
Mountain
In: Dread Return
Iron Myr
Blood Crypt

Changes Oct/21
Out: Thoughtpicker Witch
Falkenrath Aristocrat
Tomb Robber
Shriekmaw
Mad Prophet
1x Mountain
1x Swamp
In:
Woe Strider
K'rrik Son of Yawgmoth
Fleshwrither
Diamond Lion
Birgi, God of Storytelling
Command Tower
Myriad Landscape