How can you create a combo with Magus of the Coffers, Umbral Mantle?
user
[START OF COMBO]This combo can be formed with Magus of the Coffers, Umbral Mantle

Color identity: B
Mana cost: 
Steps:
  1. Attach Umbral Mantle to Magus of the Coffers.
  2. Pay {2} to activate Magus of the Coffers, adding at least six {B}.
  3. Pay {3} to activate Umbral Mantle, untapping Magus of the Coffers.
  4. Repeatedly tap the Magus for mana and untap it, generating at least {B} per iteration.[END OF COMBO STEPS]

Result:
  - Infinite black mana[END OF COMBO RESULT][END OF COMBO]

Other prerequisites:
  - All permanants must be on the battlefield
  - Magus of the Coffers is not summoning sick and can tap for mana.
  - At least six Swamps under your control.
  - {2} to start the combo.
[END OF COMBO PREREQUISITES]
assistant