How can you create a combo with River Song, Kylox's Voltstrider, Walk the Aeons?
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[START OF COMBO]This combo can be formed with River Song, Kylox's Voltstrider, Walk the Aeons

Color identity: UR
Mana cost: {4}{U}{U} each turn
Steps:
  1. Cast Walk the Aeons by paying {4}{U}{U}, causing you to take an extra turn after this one.
  2. Move to your next turn.
  3. Activate Kylox's Voltstrider's first ability by exiling Walk the Aeons from your graveyard, causing Kylox's Voltstrider to become an artifact creature until end of turn.
  4. Declare Kylov's Voltstrider as an attacker.
  5. Kylox's Voltstrider triggers, causing you to pay {4}{U}{U} to cast Walk the Aeons from exile.
  6. Resolve Walk the Aeons, causing you to take an extra turn after this one, and put Walk the Aeons on the bottom of your library.
  7. Move to your next turn, drawing Walk the Aeons from the bottom of your library due to River Song.
  8. Repeat.[END OF COMBO STEPS]

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

Other prerequisites:
  - River Song must be on the battlefield
  - Kylox's Voltstrider must be on the battlefield
  - Walk the Aeons must be in your hand
  - An opponent cannot block and kill Kylox's Voltstrider
[END OF COMBO PREREQUISITES]
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