How can you create a combo with Mystic Sanctuary, Kefnet the Mindful, Walk the Aeons?
user
[START OF COMBO]This combo can be formed with Mystic Sanctuary, Kefnet the Mindful, Walk the Aeons

Color identity: U
Mana cost: {7}{U}{U}{U}
Steps:
  1. Cast Walk the Aeons by paying {4}{U}{U}, getting an extra turn after this one.
  2. Play Mystic Sanctuary to put Walk the Aeons on top of your library.
  3. Activate Kefnet the Mindful by paying {3}{U}, causing you to draw a card and returning Mystic Sanctuary to your hand.
  4. Move to your next turn.
  5. Repeat.[END OF COMBO STEPS]

Result:
  - Infinite turns[END OF COMBO RESULT][END OF COMBO]

Other prerequisites:
  - Mystic Sanctuary must be in your hand
  - Kefnet the Mindful must be on the battlefield
  - Walk the Aeons must be in your hand
  - You control at least three additional Islands.
[END OF COMBO PREREQUISITES]
assistant