Blade of the Bloodchief + Animation Module + Krark-Clan Ironworks
Blade of the Bloodchief
Animation Module
Krark-Clan Ironworks
Infinite colorless manaInfinite death triggersInfinite creature ETBInfinite creature LTBInfinite creature sacrifice triggersInfinite +1/+1 counters on creatures you control
How it works
Activate Krark-Clan Ironworks by sacrificing any other artifact you control, adding CC.
Blade of the Bloodchief triggers, putting a +1/+1 counter on the creature it is attached to.
Animation Module triggers, causing you to pay 1 to create a 1/1 Servo artifact creature token.
Repeat.
Once you have infinite +1/+1 counters on the creature with Blade of the Bloodchief attached, you may activate Blade of the Bloodchief's equip ability, attaching it to another creature you control.
If you do, you may repeat step 5 for each creature you control.