How can you create a combo with Athreos, Shroud-Veiled, Ugin's Nexus, Karn, the Great Creator, Nahiri's Resolve, Ashnod's Altar?
user
[START OF COMBO]This combo can be formed with Athreos, Shroud-Veiled, Ugin's Nexus, Karn, the Great Creator, Nahiri's Resolve, Ashnod's Altar

Color identity: RWB
Mana cost: 
Steps:
  1. Activate Karn's first loyalty ability by putting a loyalty counter on it, causing Ugin's Nexus to become an artifact creature until end of turn.
  2. At the beginning of your end step, Athreos' second ability and Nahiri's Resolve trigger.
  3. Resolve the Athreos trigger, putting a coin counter on Ugin's Nexus.
  4. Holding priority, activate Ashnod's Altar by sacrificing Ugin's Nexus, adding {C}{C}.
  5. Ugin's Nexus is exiled instead of being put into your graveyard, causing you to take an extra turn after this one.
  6. Athreos' third ability triggers, causing you to return Ugin's Nexus from exile to the battlefield.
  7. Resolve the Nahiri's Resolve trigger from step 2, exiling Ugin's Nexus until your next upkeep.
  8. Move to your extra turn.
  9. At the beginning of your upkeep, Nahiri's Resolve triggers, returning Ugin's Nexus from exile to the battlefield.
  10. Repeat.[END OF COMBO STEPS]

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

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