How can you create a combo with Mikaeus, the Unhallowed, Putrid Goblin, Ashnod's Altar?
user
[START OF COMBO]This combo can be formed with Mikaeus, the Unhallowed, Putrid Goblin, Ashnod's Altar

Color identity: B
Mana cost: 
Steps:
  1. Activate Ashnod's Altar by sacrificing Putrid Goblin, adding {C}{C}.
  2. Putrid Goblin dies, triggering its persist and undying abilities.
  3. Resolve the persist trigger, returning it from your graveyard to the battlefield with a -1/-1 counter on it.
  4. Resolve the undying trigger, doing nothing.
  5. Activate Ashnod's Altar by sacrificing Putrid Goblin, adding {C}{C}.
  6. Putrid Goblin dies, triggering its undying ability, returning it from your graveyard to the battlefield with a +1/+1 counter on it.
  7. Activate Ashnod's Altar by sacrificing Putrid Goblin, adding {C}{C}.
  8. Putrid Goblin dies, triggering its persist ability, returning it from your graveyard to the battlefield with a -1/-1 counter on it.
  9. Repeat from step 5.[END OF COMBO STEPS]

Result:
  - Infinite colorless mana
  - Infinite death triggers
  - Infinite enters the battlefield
  - Infinite leaves the battlefield
  - Infinite sacrifice triggers[END OF COMBO RESULT][END OF COMBO]

Other prerequisites:
  - All permanants must be on the battlefield
[END OF COMBO PREREQUISITES]
assistant