Agatha's Soul Cauldron + Triskelion + Butcher Ghoul

Agatha's Soul Cauldron
Triskelion
Butcher Ghoul

Requires
Agatha's Soul Cauldron must be on the battlefield. Triskelion must be in exile (exiled by Agatha's Soul Cauldron). Butcher Ghoul must be on the battlefield. Butcher Ghoul has at least one +1/+1 counter on it.
Steps
  1. Activate Butcher Ghoul using Triskelion's ability by removing a +1/+1 counter from it.
  2. Repeat step 1 until Butcher Ghoul has no +1/+1 counters on it.
  3. Resolve all Butcher Ghoul abilities dealing 1 damage to Butcher Ghoul, and any remaining damage to any target(s).
  4. Butcher Ghoul dies as a state-based action due to having 0 toughness.
  5. Butcher Ghoul's undying ability triggers, returning it from your graveyard to the battlefield with a +1/+1 counter on it.
  6. Repeat.
Results
Infinite death triggers. Infinite ETB. Infinite LTB.

Yawgmoth, Thran Physician
0.07% of 5567 decks 4 decks
Meren of Clan Nel Toth
0.01% of 14905 decks 2 decks
Grenzo, Dungeon Warden
0.03% of 3267 decks 1 decks
Syr Konrad, the Grim
0.02% of 4587 decks 1 decks
Kenrith, the Returned King
0.00% of 21513 decks 1 decks
Mikaeus, the Unhallowed
0.07% of 1337 decks 1 decks
Tayam, Luminous Enigma
0.02% of 5725 decks 1 decks
Marchesa, the Black Rose
0.01% of 9321 decks 1 decks
Varina, Lich Queen
0.01% of 7044 decks 1 decks
Ziatora, the Incinerator
0.01% of 7932 decks 1 decks
Chatterfang, Squirrel General
0.01% of 16546 decks 1 decks
Francisco, Fowl Marauder // Tevesh Szat, Doom of Fools
3.57% of 28 decks 1 decks
Massacre Girl, Known Killer
0.03% of 3946 decks 1 decks
Jadar, Ghoulcaller of Nephalia
0.19% of 522 decks 1 decks
High Synergy Cards
Strangleroot Geist
67% of 6 decks +66% synergy
Young Wolf
67% of 6 decks +66% synergy
Geralf's Messenger
67% of 18 decks +66% synergy
Entomb
72% of 18 decks +65% synergy
Mikaeus, the Unhallowed
67% of 18 decks +64% synergy
Zulaport Cutthroat
72% of 18 decks +62% synergy
Birds of Paradise
83% of 6 decks +56% synergy
Dark Ritual
78% of 18 decks +56% synergy
Blood Artist
67% of 18 decks +55% synergy
Ashnod's Altar
61% of 18 decks +54% synergy
Top Cards
Worldly Tutor
67% of 6 decks +53% synergy
Llanowar Elves
67% of 6 decks +46% synergy
Diabolic Intent
61% of 18 decks +52% synergy
Gray Merchant of Asphodel
61% of 18 decks +52% synergy
Reanimate
61% of 18 decks +46% synergy
Walking Ballista
56% of 18 decks +53% synergy
Yawgmoth, Thran Physician
56% of 18 decks +52% synergy
Ayara, First of Locthwain
50% of 18 decks +46% synergy
The Meathook Massacre
50% of 18 decks +45% synergy
Buried Alive
50% of 18 decks +44% synergy
Creatures
Protean Hulk
50% of 6 decks +48% synergy
Warren Soultrader
50% of 6 decks +43% synergy
Viscera Seer
44% of 18 decks +35% synergy
Pawn of Ulamog
39% of 18 decks +37% synergy
Reassembling Skeleton
39% of 18 decks +35% synergy
Pitiless Plunderer
39% of 18 decks +31% synergy
Sifter of Skulls
33% of 18 decks +32% synergy
Gravecrawler
33% of 18 decks +31% synergy
Carrion Feeder
33% of 18 decks +28% synergy
Deathgreeter
28% of 18 decks +27% synergy
Syr Konrad, the Grim
28% of 18 decks +19% synergy
Orcish Bowmasters
28% of 18 decks +17% synergy
Mirkwood Bats
28% of 18 decks +15% synergy
Sightless Ghoul
22% of 18 decks +22% synergy
Necroskitter
22% of 18 decks +22% synergy
K'rrik, Son of Yawgmoth
22% of 18 decks +20% synergy
Woe Strider
22% of 18 decks +20% synergy
Ophiomancer
22% of 18 decks +19% synergy
Crypt Ghast
22% of 18 decks +17% synergy
Putrid Goblin
17% of 18 decks +16% synergy
Tormod, the Desecrator
17% of 18 decks +16% synergy
Blood Pet
17% of 18 decks +15% synergy
Dark Confidant
17% of 18 decks +15% synergy
Leaden Myr
17% of 18 decks +15% synergy
Vile Entomber
17% of 18 decks +15% synergy
Jadar, Ghoulcaller of Nephalia
17% of 18 decks +14% synergy
Stitcher's Supplier
17% of 18 decks +14% synergy
Drivnod, Carnage Dominus
17% of 18 decks +13% synergy
Grim Haruspex
17% of 18 decks +13% synergy
Plaguecrafter
17% of 18 decks +12% synergy
Braids, Arisen Nightmare
17% of 18 decks +9% synergy
Solemn Simulacrum
17% of 18 decks +3% synergy
Instants
Enlightened Tutor
100% of 3 decks +82% synergy
Deflecting Swat
75% of 4 decks +59% synergy
Chord of Calling
50% of 6 decks +44% synergy
Vampiric Tutor
44% of 18 decks +26% synergy
Deadly Rollick
39% of 18 decks +28% synergy
Defile
28% of 18 decks +24% synergy
Culling the Weak
28% of 18 decks +24% synergy
Vraska's Fall
22% of 18 decks +20% synergy
Cabal Ritual
22% of 18 decks +17% synergy
Corrupted Conviction
22% of 18 decks +17% synergy
Village Rites
22% of 18 decks +12% synergy
Deadly Dispute
22% of 18 decks +11% synergy
Snuff Out
17% of 18 decks +14% synergy
Sorceries
Eldritch Evolution
50% of 6 decks +45% synergy
Culling Ritual
50% of 6 decks +39% synergy
Toxic Deluge
44% of 18 decks +27% synergy
Feed the Swarm
44% of 18 decks +26% synergy
Unmarked Grave
33% of 18 decks +31% synergy
Victimize
33% of 18 decks +22% synergy
Demonic Tutor
33% of 18 decks +11% synergy
Dread Return
22% of 18 decks +17% synergy
Damnation
22% of 18 decks +14% synergy
Profane Tutor
17% of 18 decks +14% synergy
Unearth
17% of 18 decks +13% synergy
Grim Tutor
17% of 18 decks +12% synergy
Imperial Seal
17% of 18 decks +11% synergy
Sign in Blood
17% of 18 decks +7% synergy
Utility Artifacts
Phyrexian Altar
39% of 18 decks +35% synergy
Skullclamp
33% of 18 decks +21% synergy
Jet Medallion
28% of 18 decks +25% synergy
Wishclaw Talisman
28% of 18 decks +22% synergy
Bolas's Citadel
28% of 18 decks +18% synergy
Lightning Greaves
28% of 18 decks +2% synergy
Bontu's Monument
22% of 18 decks +20% synergy
Desecrated Tomb
17% of 18 decks +16% synergy
Genesis Chamber
17% of 18 decks +16% synergy
Swiftfoot Boots
17% of 18 decks -11% synergy
Enchantments
Nest of Scarabs
39% of 18 decks +38% synergy
Bastion of Remembrance
39% of 18 decks +33% synergy
Animate Dead
33% of 18 decks +24% synergy
Grave Pact
28% of 18 decks +23% synergy
Phyrexian Arena
22% of 18 decks +7% synergy
Necromancy
17% of 18 decks +14% synergy
Necropotence
17% of 18 decks +11% synergy
Utility Lands
Boseiju, Who Endures
67% of 6 decks +47% synergy
Phyrexian Tower
56% of 18 decks +47% synergy
Cabal Coffers
50% of 18 decks +39% synergy
Bojuka Bog
44% of 18 decks +14% synergy
Takenuma, Abandoned Mire
39% of 18 decks +28% synergy
Urborg, Tomb of Yawgmoth
33% of 18 decks +23% synergy
Ancient Tomb
33% of 18 decks +23% synergy
Witch's Cottage
28% of 18 decks +24% synergy
Reliquary Tower
28% of 18 decks -2% synergy
Cabal Stronghold
22% of 18 decks +19% synergy
Mortuary Mire
22% of 18 decks +17% synergy
Urza's Saga
22% of 18 decks +15% synergy
Hive of the Eye Tyrant
17% of 18 decks +16% synergy
Blast Zone
17% of 18 decks +15% synergy
Mana Artifacts
Sol Ring
100% of 18 decks +16% synergy
Arcane Signet
89% of 18 decks +17% synergy
Rakdos Signet
75% of 4 decks +45% synergy
Fellwar Stone
28% of 18 decks +7% synergy
Jeweled Lotus
22% of 18 decks +16% synergy
Chrome Mox
22% of 18 decks +16% synergy
Mana Vault
22% of 18 decks +16% synergy
Thought Vessel
22% of 18 decks +5% synergy
Throne of Eldraine
21% of 14 decks +19% synergy
Mox Diamond
17% of 18 decks +12% synergy
Mana Crypt
17% of 18 decks +8% synergy
Lands
Godless Shrine
100% of 3 decks +59% synergy
Llanowar Wastes
83% of 6 decks +58% synergy
Undergrowth Stadium
83% of 6 decks +57% synergy
Overgrown Tomb
83% of 6 decks +41% synergy
Blood Crypt
75% of 4 decks +36% synergy
Command Tower
61% of 18 decks -13% synergy
Bloodstained Mire
28% of 18 decks +17% synergy
Verdant Catacombs
28% of 18 decks +16% synergy
Exotic Orchard
22% of 18 decks -13% synergy
Cavern of Souls
17% of 18 decks +10% synergy
Fabled Passage
17% of 18 decks +7% synergy
Misty Rainforest
17% of 18 decks +5% synergy