Cast Aatchik either from your hand or from the command zone by paying {3}{B}{B}{G} plus commander tax, if applicable.
When Aatchik enters the battlefield, its first ability triggers, creating a 1/1 Insect creature token for each artifact and/or creature card in your graveyard.
Activate Phyrexian Altar eight times by sacrificing eight Insects, adding {4}{B}{B}{G}{G}.
When the Insects die, Aatchik's second ability triggers eight times, putting eight +1/+1 counters on Aatchik and causing each opponent to lose 8 life.
Activate Temur Sabertooth by paying {1}{G}, returning Aatchik from the battlefield to your hand.
Repeat.

Infinite LTB

Infinite ETB

Infinite colored mana

Infinite sacrifice triggers

Infinite death triggers

Infinite storm count

Infinite creature tokens

Infinite lifeloss

Infinite +1/+1 counters on a creature

Infinite blinking

Aatchik, Emerald Radian

Phyrexian Altar

Temur Sabertooth

Cast Aatchik either from your hand or from the command zone by paying {3}{B}{B}{G} plus commander tax, if applicable.
When Aatchik enters the battlefield, its first ability and Cloudstone Curio trigger.
Resolve the Cloustone Curio trigger, choosing to return nothing to your hand.
Resolve the Aatchik trigger, creating a 1/1 Insect creature token for each artifact and/or creature card in your graveyard.
When the Insects enter the battlefield, Cloudstone Curio triggers that many times. 
Holding priority, activate Phyrexian Altar six times by sacrificing six Insects, adding {3}{B}{B}{G}.
When the Insects die, Aatchik's second ability triggers six times, putting six +1/+1 counters on Aatchik and causing each opponent to lose 6 life.
Resolve the Cloudstone Curio triggers, returning Aatchik from the battlefield to your hand with the first trigger and returning nothing to your hand with each subsequent trigger.
Repeat.

Cloudstone Curio

Cast Aatchik either from your hand or from the command zone by paying {3}{B}{B}{G} plus commander tax, if applicable.
When Aatchik enters the battlefield, it triggers, creating a 1/1 Insect creature token for each artifact and/or creature card in your graveyard.
Activate Earthcraft twice by tapping two Insects, untapping a basic Swamp and a basic Forest.
Activate the Swamp and Forest by tapping them, adding {B}{G}.
Repeat from step 3 three additional times.
Activate Temur Sabertooth by paying {1}{G}, returning Aatchik from the battlefield to your hand.
Repeat.

Infinite mana basic lands you control can produce

Infinite untap of basic lands you control

Earthcraft

Cast Aatchik either from your hand or from the command zone by paying {3}{B}{B}{G} plus commander tax, if applicable.
When Aatchik enters the battlefield, its first ability and Cloudstone Curio trigger.
Resolve the Cloustone Curio trigger, choosing to return nothing to your hand.
Resolve the Aatchik trigger, creating a 1/1 Insect creature token for each artifact and/or creature card in your graveyard.
When the Insects enter the battlefield, Cloudstone Curio triggers that many times., returning Aatchik from the battlefield to your hand with the first trigger and returning nothing to your hand with each subsequent trigger.
Activate Earthcraft twice by tapping two Insects, untapping a basic Swamp and a basic Forest.
Activate the Swamp and Forest by tapping them, adding {B}{G}.
Repeat from step 6 two additional times.
Repeat from step 1.

Combos with "Aatchik, Emerald Radian"