How can you create a combo with Othelm, Sigardian Outcast, Myr Battlesphere, Intruder Alarm, Krark-Clan Ironworks?
user
[START OF COMBO]This combo can be formed with Othelm, Sigardian Outcast, Myr Battlesphere, Intruder Alarm, Krark-Clan Ironworks

Color identity: GWU
Mana cost: 
Steps:
  1. Activate Krark-Clan Ironworks by sacrificing Myr Battlesphere, adding {C}{C}.
  2. Activate Othelm by paying {2} and tapping it, returning Myr Battlesphere from your graveyard to the battlefield tapped.
  3. Myr Battlesphere enters the battlefield, triggering itself and Intruder Alarm.
  4. Resolve the Intruder Alarm trigger, untapping all creatures.
  5. Resolve the Myr Battlesphere trigger, creating four 1/1 Myr artifact creature tokens.
  6. The Myr tokens enter the battlefield, triggering Intruder Alarm four times, untapping all creatures.
  7. Repeat.[END OF COMBO STEPS]

Result:
  - Infinite colorless mana
  - Infinite creature tokens
  - Infinite death triggers
  - Infinite enters the battlefield
  - Infinite leaves the battlefield
  - Infinite mana creatures you control can produce
  - Infinite sacrifice triggers
  - Infinite tap triggers
  - Infinite untap of all creatures[END OF COMBO RESULT][END OF COMBO]

Other prerequisites:
  - All permanants must be on the battlefield
  - Othelm does not have summoning sickness.
[END OF COMBO PREREQUISITES]
assistant