How can you create a combo with Boonweaver Giant, Fool's Demise, Phyrexian Altar?
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[START OF COMBO]This combo can be formed with Boonweaver Giant, Fool's Demise, Phyrexian Altar

Color identity: WU
Mana cost: 
Steps:
  1. Activate Phyrexian Altar by sacrificing Boonweaver Giant, adding one mana of any color.
  2. Boonweaver Giant dies, triggering Fool's Demise's first and second abilities.
  3. Resolve Fool's Demise's first trigger, returning Boonweaver Giant to the battlefield.
  4. Boonweaver Giant enters the battlefield, returning Fool's Demise from your graveyard to the battlefield attached to Boonweaver Giant.
  5. Fool's Demise's second trigger from step 2 fails to resolve  due to having no legal target.
  6. Repeat.[END OF COMBO STEPS]

Result:
  - Infinite colored 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
  - Fool's Demise attached to Boonweaver Giant.
[END OF COMBO PREREQUISITES]
assistant