Infinite colorless manaInfinite creature tokensInfinite death triggersInfinite creature ETBInfinite creature LTBInfinite mana creatures you control can produceInfinite creature sacrifice triggersInfinite untap of creatures
How it works
Activate Ashnod's Altar by sacrificing Myr Battlesphere, adding CC.
Activate Othelm by paying 2 and tapping it, returning Myr Battlesphere from your graveyard to the battlefield tapped.
Myr Battlesphere enters the battlefield, triggering itself and Intruder Alarm.
Resolve the Intruder Alarm trigger, untapping all creatures.
Resolve the Myr Battlesphere trigger, creating four 1/1 Myr artifact creature tokens.
The Myr tokens enter the battlefield, triggering Intruder Alarm four times, untapping all creatures.