Activate Ashnod's Altar by sacrificing Clockwork Hydra.
When Clockwork Hydra dies, its persist ability triggers, returning it from your graveyard to the battlefield without a -1/-1 counter on it due to its replacement effect.
Repeat.

Infinite creature ETB

Infinite creature LTB

Infinite colorless mana

Infinite death triggers

Infinite creature sacrifice triggers

Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight

Ashnod's Altar

Clockwork Hydra

Activate Arcbound Ravager by sacrificing Clockwork Hydra.
When Clockwork Hydra dies, its persist ability triggers, returning it from your graveyard to the battlefield without a -1/-1 counter on it due to its replacement effect.
Resolve the Arcbound Ravager ability.
Repeat.
Kill Arcbound Ravager.
When Arcbound Ravager dies, its persist ability triggers, returning Arcbound Ravager from your graveyard to the battlefield. It will have no counters on it due to its modular ability.
Arcbound Ravager dies as a state-based action due to having 0 toughness
Repeat from step 2.

Draw the game

Infinite +1/+1 counters on a creature

Infinite artifact ETB

Infinite artifact LTB

Infinite artifact sacrifice triggers

Arcbound Ravager

Activate Berta using Clockwork Hydra's ability by tapping them, putting a +1/+1 counter on Berta.
Berta's second ability triggers, adding one mana of any color.
Activate Berta using Farmstead Gleaner's ability by paying {2} and untapping them, putting a +1/+1 counter on Berta.
Berta's second ability triggers, adding one mana of any color.
Repeat.

Berta, Wise Extrapolator

Agatha's Soul Cauldron

Farmstead Gleaner

Combos with "Clockwork Hydra"