How can you create a combo with Sai, Master Thopterist, Myr Retriever, Scrap Trawler, Ashnod's Altar?
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[START OF COMBO]This combo can be formed with Sai, Master Thopterist, Myr Retriever, Scrap Trawler, Ashnod's Altar

Color identity: U
Mana cost: 
Steps:
  1. Activate Ashnod's Altar by sacrificing Scrap Trawler, adding {C}{C}.
  2. When Scrap Trawler dies, it triggers, returning Myr Retriever from your graveyard to your hand.
  3. Cast Myr Retriever by paying {2}.
  4. Sai triggers, creating a 1/1 Thopter artifact creature token.
  5. Activate Ashnod's Altar twice by sacrificing the Thopter and Myr Retriever, adding {C}{C}{C}{C}.
  6. When Myr Retriever dies, it triggers, returning Scrap Trawler from your graveyard to your hand.
  7. Cast Scrap Trawler by paying {3}.
  8. Sai triggers, creating a 1/1 Thopter artifact creature token.
  9. Repeat.[END OF COMBO STEPS]

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

Other prerequisites:
  - Sai, Master Thopterist must be on the battlefield
  - Myr Retriever must be in the graveyard
  - Scrap Trawler must be on the battlefield
  - Ashnod's Altar must be on the battlefield
[END OF COMBO PREREQUISITES]
assistant