Arcane Bombardment + Inspiring Refrain + Jhoira's Timebug + Walk the Aeons + Time Warp

Arcane Bombardment

Inspiring Refrain

Jhoira's Timebug

Walk the Aeons

Time Warp

How it works

1. Cast Inspiring Refrain by paying 4.
2. Arcane Bombardment triggers, exiling a random instant or sorcery from your graveyard, and then casting a copy of Time Warp and Walk the Aeons without paying their mana costs.
3. Resolve the Time Warp and Walk the Aeons copies, causing you to take two extra turns after this one.
4. Resolve Inspiring Refrain, causing you to draw two cards and exile Inspiring Refrain with three time counters on it.
5. Activate Jhoira's Timebug by tapping it, removing a time counter from Inspiring Refrain.
6. Move to your first extra turn, removing a time counter from Inspiring Refrain during your upkeep.
7. Move to your second extra turn, removing a time counter from Inspiring Refrain during your upkeep.
8. Inspiring Refrain triggers, causing you to cast it from exile without paying its mana cost.
9. Repeat from step 2.