Activate Ashnod's Altar by sacrificing another creature, adding {C}{C}.
When the creature dies, Ob Nixilis' second ability triggers, putting a +1/+1 counter on Ob Nixilis.
Animation Module triggers, causing you to pay {1} to create a 1/1 Servo artifact creature token.
Repeat.

Infinite +1/+1 counters on a creature

Infinite colorless mana

Infinite death triggers

Infinite ETB

Infinite LTB

Infinite sacrifice triggers

Ob Nixilis, Unshackled

Animation Module

Ashnod's Altar

Activate Phyrexian Altar by sacrificing another creature, adding {1}.
When the creature dies, Ob Nixilis' second ability triggers, putting a +1/+1 counter on Ob Nixilis.
Animation Module triggers, causing you to pay {1} to create a 1/1 Servo artifact creature token.
Repeat.

Phyrexian Altar

Activate Field, targeting a land and triggering Rings of Brighthearth.
Pay to copy the Field effect, targeting a different land.
Resolve both triggers and the resulting Ob Nixilis triggers, forcing all opponent to lose 20 life.
Use Crucible of Worlds to play Field.
Repeat steps 1-3.

Near-infinite lifeloss

Field of Ruin

Rings of Brighthearth

Crucible of Worlds

Activate Field of Ruin's second ability by paying {2}, tapping and sacrificing it, targeting any nonbasic land an opponent controls.
Holding priority, cast Radiant Performer by paying {3}{R}{R}.
When Radiant Performer enters the battlefield, it triggers, copying Field of Ruin's ability for each other nonbasic land your opponents control.
Resolve the first Field of Ruin ability, destroying the land it it targeting, then causing each player to search their library for a basic land card and put it onto the battlefield.
Ob Nixilis' first ability triggers for each opponent who searches this way, causing each opponent to sacrifice a creature and lose 10 life.
Repeat from step 4 for each other Field of Ruin ability.

Radiant Performer

Activate Krark-Clan Ironworks by sacrificing an artifact creature, adding {C}{C}.
When the creature dies, Ob Nixilis' second ability triggers, putting a +1/+1 counter on Ob Nixilis.
Animation Module triggers, causing you to pay {1} to create a 1/1 Servo artifact creature token.
Repeat.

Krark-Clan Ironworks

Cast Storm King's Thunder by paying {R}{R}{R} plus an additional {1} for every twenty life your opponents collectively have, copying the next instant or sorcery spell you cast that many times.
Cast Scheming Symmetry by paying {B}.
Storm King's Thunder triggers, copying Scheming Symmetry at least once.
Resolve a Scheming Symmetry, causing two opponents to search their library for a card, and then shuffle their libraries and put the card on top of it.
Ob Nixilis triggers for each opponent who searched their library, causing them to lose ten life.
Repeat from step 4 for each remaining Scheming Symmetry.

Combos with "Ob Nixilis, Unshackled"