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

Arcane Bombardment

Inspiring Refrain

Jhoira's Timebug

Time Walk

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 Walk and Time Warp without paying their mana costs.
3. Resolve the Time Walk and Time Warp 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.

This brilliant loop sets up an unstoppable chain of extra turns by chaining the devastating power of Time Walk and Time Warp through the repeatable triggers of Arcane Bombardment. When you cast Inspiring Refrain, the Bombardment steps in to copy and fire off your extra-turn spells for free while sending the Refrain back into exile with its time counters. To ensure the engine never stalls out, Jhoira's Timebug accelerates those time counters away so you can constantly recast Inspiring Refrain on your extra turns and keep the Arcane Bombardment triggering turn after turn.