How can you create a combo with Athreos, Shroud-Veiled, Ugin's Nexus, Karn, Silver Golem, Master Transmuter, Ashnod's Altar?
user
[START OF COMBO]This combo can be formed with Athreos, Shroud-Veiled, Ugin's Nexus, Karn, Silver Golem, Master Transmuter, Ashnod's Altar

Color identity: WUB
Mana cost: {1}{U} the first turn, with {6}{U} available each extra turn
Steps:
  1. Activate Karn by paying {1}, causing Ugin's Nexus to become an artifact creature until end of turn.
  2. At the beginning of your end step, Athreos' second ability triggers, putting a coin counter on Ugin's Nexus.
  3. Activate Ashnod's Altar by sacrificing Ugin's Nexus, adding {C}{C}.
  4. Ugin's Nexus is exiled instead of being put into your graveyard, causing you to take an extra turn after this one.
  5. Athreos' third ability triggers, causing you to return Ugin's Nexus from exile to the battlefield.
  6. Activate Master Transmuter by paying {U}, tapping it and returning Ugin's Nexus to your hand, choosing to not put an artifact onto the battlefield.
  7. Move to your extra turn.
  8. Cast Ugin's Nexus by paying {5}.
  9. Repeat.[END OF COMBO STEPS]

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

Other prerequisites:
  - All permanants must be on the battlefield
  - Master Transmuter does not have summoning sickness.
[END OF COMBO PREREQUISITES]
assistant