Cauldron of Souls + Corridor Monitor + Cathars' Crusade + Altar of Dementia

Cauldron of Souls
Corridor Monitor
Cathars' Crusade
Altar of Dementia

Requires
Cauldron of Souls must be on the battlefield. Corridor Monitor must be on the battlefield. Cathars' Crusade must be on the battlefield. Altar of Dementia must be on the battlefield. Corridor Monitor does not have a -1/-1 counter on it.
Steps
  1. Activate Cauldron of Souls by tapping it, giving Corridor Monitor persist until end of turn.
  2. Activate Altar of Dementia by sacrificing Corridor Monitor.
  3. When Corridor Monitor dies, its persist ability triggers, returning itself from your graveyard to the battlefield with a -1/-1 counter on it.
  4. When Corridor Monitor enters the battlefield, it and Cathars' Crusade trigger.
  5. Resolve the Corridor Monitor trigger, untapping Cauldron of Souls.
  6. Resolve the Cathars' Crusade trigger, putting a +1/+1 counter on each creature you control.
  7. Resolve the Altar of Dementia ability from step 2, causing target player to mill cards equal to Corridor Monitor's power.
  8. Repeat.
Results
Infinite death triggers. Infinite ETB. Infinite LTB. Infinite mill. Infinite sacrifice triggers. Infinite self-mill. Infinite +1/+1 counters.

Reaper King
0.04% of 5423 decks 2 decks
Creatures
Grand Architect
100% of 2 decks +100% synergy
Painter's Servant
100% of 2 decks +100% synergy
Tatterkite
100% of 2 decks +100% synergy
Rattleblaze Scarecrow
100% of 2 decks +100% synergy
Antler Skulkin
100% of 2 decks +100% synergy
Luminous Broodmoth
100% of 2 decks +100% synergy
Changeling Titan
100% of 2 decks +100% synergy
Changeling Hero
100% of 2 decks +100% synergy
Changeling Berserker
100% of 2 decks +99% synergy
Wingrattle Scarecrow
100% of 2 decks +99% synergy
Pili-Pala
100% of 2 decks +99% synergy
Scarecrone
100% of 2 decks +99% synergy
Metallic Mimic
100% of 2 decks +98% synergy
Three Tree Mascot
100% of 1 decks +94% synergy
Maw of the Obzedat
50% of 2 decks +50% synergy
Good-Fortune Unicorn
50% of 2 decks +50% synergy
Mikaeus, the Unhallowed
50% of 2 decks +50% synergy
Scrapbasket
50% of 2 decks +50% synergy
Clone
50% of 2 decks +50% synergy
Wild-Field Scarecrow
50% of 2 decks +49% synergy
Scaretiller
50% of 2 decks +49% synergy
Scuttlemutt
50% of 2 decks +49% synergy
Displacer Kitten
50% of 2 decks +47% synergy
Spark Double
50% of 2 decks +47% synergy
Bloodline Pretender
50% of 2 decks +47% synergy
Realmwalker
50% of 2 decks +41% synergy
Esper Sentinel
50% of 2 decks +41% synergy
Instants
First Day of Class
100% of 2 decks +100% synergy
Rapid Hybridization
100% of 2 decks +99% synergy
Chaos Warp
100% of 2 decks +94% synergy
Beast Within
100% of 2 decks +85% synergy
Cyclonic Rift
100% of 2 decks +79% synergy
Mystical Teachings
50% of 2 decks +50% synergy
Cryptic Command
50% of 2 decks +50% synergy
Stinging Study
50% of 2 decks +49% synergy
Force of Negation
50% of 2 decks +46% synergy
Force of Will
50% of 2 decks +43% synergy
Brainstorm
50% of 2 decks +43% synergy
Mystical Tutor
50% of 2 decks +43% synergy
Generous Gift
50% of 2 decks +42% synergy
Mana Drain
50% of 2 decks +41% synergy
Enlightened Tutor
50% of 2 decks +34% synergy
Counterspell
50% of 2 decks +29% synergy
Path to Exile
50% of 2 decks +25% synergy
Swords to Plowshares
50% of 2 decks +9% synergy
Sorceries
Deathbellow War Cry
100% of 2 decks +100% synergy
Rite of Replication
100% of 2 decks +98% synergy
Fireball
50% of 2 decks +50% synergy
Personal Tutor
50% of 2 decks +49% synergy
Fabricate
50% of 2 decks +47% synergy
Utility Artifacts
Grindstone
100% of 2 decks +100% synergy
Ashnod's Altar
100% of 2 decks +98% synergy
Amulet of Vigor
100% of 2 decks +97% synergy
The Great Henge
100% of 2 decks +94% synergy
Voltaic Key
50% of 2 decks +50% synergy
Phyrexian Altar
50% of 2 decks +49% synergy
Clock of Omens
50% of 2 decks +48% synergy
Unwinding Clock
50% of 2 decks +46% synergy
The One Ring
50% of 2 decks +41% synergy
Lightning Greaves
50% of 2 decks +32% synergy
Enchantments
Solemnity
100% of 2 decks +100% synergy
Storm the Vault
100% of 2 decks +99% synergy
Rhythm of the Wild
50% of 2 decks +39% synergy
Rhystic Study
50% of 2 decks +26% synergy
Utility Lands
Dark Depths
100% of 2 decks +99% synergy
Thespian's Stage
100% of 2 decks +97% synergy
Arcane Lighthouse
50% of 2 decks +49% synergy
Mana Artifacts
Talisman of Indulgence
100% of 2 decks +98% synergy
Talisman of Hierarchy
100% of 2 decks +98% synergy
Talisman of Conviction
100% of 2 decks +98% synergy
Talisman of Unity
100% of 2 decks +98% synergy
Talisman of Progress
100% of 2 decks +98% synergy
Talisman of Creativity
100% of 2 decks +97% synergy
Talisman of Impulse
100% of 2 decks +96% synergy
Talisman of Resilience
100% of 2 decks +96% synergy
Talisman of Dominance
100% of 2 decks +96% synergy
Talisman of Curiosity
100% of 2 decks +95% synergy
Mana Vault
100% of 2 decks +94% synergy
Timeless Lotus
100% of 2 decks +86% synergy
Sol Ring
100% of 2 decks +22% synergy
Sol Talisman
50% of 2 decks +49% synergy
Arcane Signet
50% of 2 decks -24% synergy
Lands
Reflecting Pool
100% of 2 decks +85% synergy
Blood Crypt
100% of 2 decks +77% synergy
Sacred Foundry
100% of 2 decks +76% synergy
Steam Vents
100% of 2 decks +75% synergy
Watery Grave
100% of 2 decks +75% synergy
Godless Shrine
100% of 2 decks +75% synergy
Hallowed Fountain
100% of 2 decks +72% synergy
Stomping Ground
100% of 2 decks +70% synergy
Overgrown Tomb
100% of 2 decks +70% synergy
Breeding Pool
100% of 2 decks +70% synergy
Temple Garden
100% of 2 decks +70% synergy
Command Tower
100% of 2 decks +12% synergy
Vivid Marsh
50% of 2 decks +48% synergy
Vivid Meadow
50% of 2 decks +48% synergy
Vivid Crag
50% of 2 decks +48% synergy
Vivid Creek
50% of 2 decks +48% synergy
Drowned Catacomb
50% of 2 decks +48% synergy
Isolated Chapel
50% of 2 decks +48% synergy
Clifftop Retreat
50% of 2 decks +48% synergy
Glacial Fortress
50% of 2 decks +48% synergy
Vivid Grove
50% of 2 decks +47% synergy
Dragonskull Summit
50% of 2 decks +47% synergy
Sulfur Falls
50% of 2 decks +47% synergy
Woodland Cemetery
50% of 2 decks +47% synergy
Rootbound Crag
50% of 2 decks +47% synergy
Sunpetal Grove
50% of 2 decks +47% synergy
Hinterland Harbor
50% of 2 decks +47% synergy
Luxury Suite
50% of 2 decks +44% synergy
Vault of Champions
50% of 2 decks +44% synergy
Spectator Seating
50% of 2 decks +44% synergy
Morphic Pool
50% of 2 decks +44% synergy
Training Center
50% of 2 decks +44% synergy
Undergrowth Stadium
50% of 2 decks +43% synergy
Sea of Clouds
50% of 2 decks +43% synergy
Spire Garden
50% of 2 decks +43% synergy
Bountiful Promenade
50% of 2 decks +42% synergy
Rejuvenating Springs
50% of 2 decks +42% synergy
Badlands
50% of 2 decks +38% synergy
Plateau
50% of 2 decks +38% synergy
Scrubland
50% of 2 decks +38% synergy
Volcanic Island
50% of 2 decks +38% synergy
Underground Sea
50% of 2 decks +38% synergy
Tundra
50% of 2 decks +37% synergy
Savannah
50% of 2 decks +37% synergy
Taiga
50% of 2 decks +37% synergy
Bayou
50% of 2 decks +37% synergy
Tropical Island
50% of 2 decks +37% synergy
Mana Confluence
50% of 2 decks +30% synergy
City of Brass
50% of 2 decks +29% synergy
Exotic Orchard
50% of 2 decks -13% synergy