How can you create a combo with Horseshoe Crab, Mesmeric Orb, Multani's Harmony?
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[START OF COMBO]This combo can be formed with Horseshoe Crab, Mesmeric Orb, Multani's Harmony

Color identity: GU
Mana cost: 
Steps:
  1. Activate Horseshoe Crab by tapping it, adding {U}.
  2. Activate Horseshoe Crab by paying {U}, untapping Horseshoe Crab.
  3. Mesmeric Orb triggers, causing you to mill a card.
  4. Repeat.[END OF COMBO STEPS]

Result:
  - Infinite self-mill
  - Infinite tap triggers[END OF COMBO RESULT][END OF COMBO]

Other prerequisites:
  - All permanants must be on the battlefield
  - Horseshoe Crab does not have summoning sickness.
  - Multani's Harmony attached to Horseshoe Crab.
[END OF COMBO PREREQUISITES]
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