Activate Goblin Engineer by paying {R}, tapping it and sacrificing a nontoken artifact creature with mana value 3 or less, targeting another artifact creature with mana value 3 or less in your graveyard.
When the artifact creature dies, Goblin Engineer and Crime Novelist triggers.
Resolve the Goblin Engineer trigger, untapping it.
Resolve the Crime Novelist trigger, putting a +1/+1 counter on it and adding {R}.
Resolve the Goblin Engineer ability, returning the targeted artifact creature from your graveyard to the battlefield.
Repeat.

Infinite artifact ETB

Infinite artifact LTB

Infinite artifact sacrifice triggers

Infinite +1/+1 counters on a creature

Infinite creature ETB

Infinite creature LTB

Infinite death triggers

Infinite creature sacrifice triggers

Goblin Engineer

Crime Novelist

Thornbite Staff

Activate Commander's Sphere's first ability by tapping it, adding {R}.
Activate Commander's Sphere's second ability by sacrificing it, causing you to draw a card.
Activate Goblin Engineer by paying {R}, tapping and sacrificing Corridor Monitor, targeting Commander's Sphere.
Ashnod triggers, copying Goblin Engineer's ability, targeting Corridor Monitor.
Resolve the first Goblin Engineer ability, returning Corridor Monitor from your graveyard to the battlefield.
Corridor Monitor enters the battlefield, untapping Goblin Engineer.
Resolve the second Goblin Engineer ability, returning Commander Sphere from your graveyard to the battlefield.
Repeat.

Infinite card draw

Infinite draw triggers

Near-infinite death triggers

Near-infinite creature ETB

Near-infinite creature LTB

Near-infinite creature sacrifice triggers

Ashnod the Uncaring

Corridor Monitor

Commander's Sphere

Activate Goblin Engineer by paying {R}, tapping it and sacrificing a nontoken artifact creature with mana value 3 or less, targeting another artifact creature with mana value 3 or less in your graveyard.
When the artifact creature dies, Goblin Engineer and Crime Novelist triggers, putting a +1/+1 counter on it and adding {R}.
Resolve the Goblin Engineer ability, returning the targeted artifact creature from your graveyard to the battlefield.
When the artifact creature enters, Intruder Alarm triggers, untapping all creatures.
Repeat.

Infinite mana creatures you control can produce

Infinite untap of creatures

Intruder Alarm

Activate Lotus Petal by tapping and sacrificing it, adding {R}.
Activate Goblin Engineer by paying {R}, tapping and sacrificing Corridor Monitor, targeting Lotus Petal.
Ashnod triggers, copying Goblin Engineer's ability, targeting Corridor Monitor.
Resolve the first Goblin Engineer ability, returning Corridor Monitor from your graveyard to the battlefield.
Corridor Monitor enters the battlefield, untapping Goblin Engineer.
Resolve the second Goblin Engineer ability, returning Commander Sphere from your graveyard to the battlefield.
Repeat.

Lotus Petal

Combos with "Goblin Engineer"