I'm including brief summaries after each point so that the lines will be more obvious without having to read through any point multiple times.
This is a fast combo deck that also leverages reanimating large value engines. These engines are Nezahal, for when you need an engine with more staying power, Villis, for when you need an engine with more interaction, and Razaketh, for when you are trying to win off a single Entomb + reanimate spell.
Entomb one of these creatures + Reanimate = value
The deck also runs Seedborn Muse, which can be reanimated in grindier games to generate value off of Thrasios. Seedborn Muse can also can be searched out by Eldritch Evolution , sacrificing Vial Smasher.
Vial Smasher + Eldritch Evolution = Seedborn Muse
The abundance of reanimation spells works in tandem with the deck's primary win condition: reanimating Necrotic Ooze. The Necrotic Ooze combo this deck takes advantage of is having Morselhoarder + Devoted Druid in the graveyard, allowing you to generate infinite mana.
Necrotic Ooze in play + Morselhoarder and Devoted Druid in graveyard = infinite mana
With Thrasios as the outlet of the mana you can then win using either Finale of Devestation, Walking Ballista, or Thassa's Oracle. The appeal of this combo is that, once Necrotic Ooze hits the field with the other two cards in the graveyard, there is no point between making infinite mana and passing priority.
Thraios + Infinite mana
This combo is most easily assembled using Buried Alive and a reanimation spell, or by activating Hermit Druid to mill your library and flashing back Dread Return targeting Necrotic Ooze. Survival of the Fittest can also be used to assemble this combo, and the mana to assemble it can be spent over two turn cycles.
Buried Alive + Reanimate
Hermit Druid + two other creatures + G
Survival of the Fittest + creature in hand + GGG + 2BB (if you are hardcasting Necrotic Ooze)
Survival of the Fittest + creature in hand + GGGG + reanimate spell (if you are reanimating Necrotic Ooze)
Thassa's Oracle is included in the deck as an additional Dread Return target, as well as allowing for lines with Demonic Consultation and Tainted Pact as a secondary combo.
Thassa's Oracle + Demonic Consultation or Tainted Pact
The tertiary combo in the deck is Dockside Extortionist and Temur Sabertooth, assuming your opponents have a combined total artifact and enchantment count of five. This will also generate infinite mana, allowing you to win through Thrasios.
Dockside Extortionist + Temur Sabertooth + opponents have a combined total artifact and enchantment count of five = infinite mana
Neoform can be used to turn Vial Smasher into a Necrotic Ooze, or an elf into a Hermid Druid, while Eldritch Evolution can turn Thrasios into Necrotic Ooze, or anything into Hermit Druid.
Neoform + Vial Smasher = Necrotic Ooze
Neoform + Elf = Hermit Druid
Eldritch Evolution + Thrasios = Necrotic Ooze
Eldritch Evolution + any creature = Hermit Druid
An interesting perk of running Necrotic Ooze is that, in addition to being the primary win condition, it can function as other combo pieces. With Hermit Druid in the graveyard, Necrotic Ooze can mill Devoted Druid and Morselhoarder into the graveyard, enabling its own combo. Necrotic Ooze can also fill the role of Temur Sabertooth in the Dockside combo (assuming Sabertooth has found its way into your graveyard). Necrotic Ooze also does a good impression of Razaketh when he is in the graveyard.
Dockside Extortionist + Necrotic Ooze + Temur Sabertooth in graveyard + opponents have a combined total artifact and enchantment count of five = infinite mana
Necrotic Ooze + Hermit Druid in graveyard + G
One notable inclusion in the deck is Haunted Dead, and I can understand why someone may question its inclusion. The reason for this card is because it is a very strong role filler for the Hermit Druid line, allowing you to Dread Return with the only board state required being Hermit Druid (not summoning sick) in play, two cards in hand, and 1BG. Because Haunted Dead creates a token when it enters the battlefield it provides you with the two additional bodies to sacrifice to flashback Dread Return. In addition, Haunted Dead solves the problem of awkwardly having any of your combo pieces in hand that need to be in your graveyard. So this kind of terrible card fills the role that I have seen filled by cards suck as Bloodghast, Narcomeba, and Cabal Therapy, while being about as good as the two former in terms of card quality and only taking up one card slot instead of potentially three.
Hermit Druid + 1BG + two cards in hand
Two notable exclusions in a reanimator deck are Jin-Gixatias and Consecrated Sphinx. The main reason they are left out of the list is because I found I was very rarely wanting them to be the creature I was reanimating, and when I did reanimate them they were often removed before they could have much, if any, effect.
Grafdigger's Cage being a reliable counter to Flash Hulk resulted in this deck commonly being shut down as well, but with the banning of Flash i am hopeful that the deck will function properly on a more regular basis. Both non primary combos were added because they completely avoid any sort of graveyard hate.
