Cast Time Warp by paying its mana cost, causing you to take an extra turn after this one.
Cast Ephemerate by paying , blinking The Immortal Weapons and exiling Ephemerate.
When The Immortal Weapons enters, it triggers, returning Time Warp from your graveyard to your hand.
Move to your next turn. At the beginning of your upkeep, Ephemerate's rebound ability triggers, causing you to cast it from exile without paying its mana cost.
Resolve Ephemerate, blinking The Immortal Weapons.
When The Immortal Weapons enters, it triggers, returning Ephemerate from your graveyard to your hand.