Tayam, Luminous Enigma + Mortician Beetle + Ashnod's Altar + Safehold Elite
Infinite Mana: Infinite +1/+1 counters on a creature, Infinite colorless mana, Infinite death triggers, Infinite ETB, Infinite LTB, Infinite sacrifice triggers, Infinite self-mill, Put a selection of permanant cards from your library and graveyard onto the battlefield
Activate Ashnod's Altar by sacrificing Safehold Elite, adding {C}{C}.
Safehold Elite's persist ability and Mortician Beetle trigger.
Resolve the Safehold Elite trigger, returning it from your graveyard to the battlefield with a -1/-1 and a vigilance counter.
Resolve the Mortician Beetle trigger, putting a +1/+1 counter on it.
Activate Tayam by paying {3}, removing a +1/+1 counter from Mortician Beetle and removing both counters from Safehold Elite.
Holding priority, activate Ashnod's Altar by sacrificing Safehold Elite, adding {C}{C}.
Safehold Elite's persist ability and Mortician Beetle trigger.
Resolve the Safehold Elite trigger, returning it from your graveyard to the battlefield with a -1/-1 and a vigilance counter.
Resolve the Mortician Beetle trigger, putting a +1/+1 counter on it.
Activate Ashnod's Altar by sacrificing Safehold Elite, adding {C}{C}.
Mortician Beetle triggers, putting a +1/+1 counter on itself.
Resolve the Tayam ability from step 5, causing yourself to mill three cards and return Safehold Elite from your graveyard to the battlefield.
Repeat.
Cards: Tayam, Luminous Enigma, Mortician Beetle, Ashnod's Altar, Safehold Elite