How can you create a combo with Keiga, the Tide Star, Nim Deathmantle, Ashnod's Altar?
user
[START OF COMBO]This combo can be formed with Keiga, the Tide Star, Nim Deathmantle, Ashnod's Altar

Color identity: U
Mana cost: 
Steps:
  1. Whenever an opponent controls a creature, activate Ashnod's Altar by sacrificing Keiga, adding {C}{C}.
  2. When Keiga dies, it and Nim Deathmantle trigger.
  3. Resolve the Keiga trigger, causing you to gain control of a creature an opponent controls.
  4. Activate Ashnod's Altar by sacrificing the creature you gained control of in step 3, adding {C}{C}.
  5. Resolve the Nim Deathmantle trigger from step 2, causing you to pay {4} to return Keiga from your graveyard to the battlefield, and attach Nim Deathmantle to it.
  6. Repeat as desired and/or whenever a creature enters the battlefield under an opponent's control.[END OF COMBO STEPS]

Result:
  - Gain control of all creatures opponents control and sacrifice them
  - Gain control of any creature that enters the battlefield under an opponent's control[END OF COMBO RESULT][END OF COMBO]

Other prerequisites:
  - All permanants must be on the battlefield
[END OF COMBO PREREQUISITES]
assistant