How can you create a combo with Saheeli, the Sun's Brilliance, Umbral Mantle, Great Whale?
user
[START OF COMBO]This combo can be formed with Saheeli, the Sun's Brilliance, Umbral Mantle, Great Whale

Color identity: UR
Mana cost: 
Steps:
  1. Activate up to seven lands by tapping them, adding at least {3}{U}{R}.
  2. Activate Saheeli by paying {U}{R} and tapping it, creating a token copy of Great Whale with haste.
  3. When the token Great Whale enters the battlefield, it triggers, untapping up to seven lands.
  4. Repeat.
  5. If you control up to seven lands that can tap to produce at least {4}{U}{R}, this combo nets infinite mana, and you may target any other creature(s) or artifact(s) using Saheeli's ability.[END OF COMBO STEPS]

Result:
  - Infinite copies of artifacts you control
  - Infinite copies of creatures you control with haste
  - Infinite creature tokens with haste
  - Infinite death triggers
  - Infinite enters the battlefield
  - Infinite leaves the battlefield
  - Infinite mana lands you control can produce
  - Infinite sacrifice triggers
  - Infinite untap of lands you control[END OF COMBO RESULT][END OF COMBO]

Other prerequisites:
  - All permanants must be on the battlefield
  - Umbral Mantle attached to Saheeli.
  - Saheeli does not have summoning sickness.
  - You control up to seven lands that can tap to produce at least {3}{U}{R}.
[END OF COMBO PREREQUISITES]
assistant